Got questions about gardening in Maine?

Extension experts identifies a plant sample for a client; photo by Edwin Remsberg

Ask the UMaine Extension gardening experts!

With years of experience in home horticulture and commercial agriculture, our experts help beginning gardeners achieve successful harvests, encourage gardeners and commercial farmers to donate excess produce to those in need, and use gardening as a vehicle to develop communities.

If you have a question about growing vegetables and fruit in Maine, you are welcome to

Summer 2020 Q&A

Answers are provided by Donna Coffin, Extension Professor, Penobscot & Piscataquis Counties; Caragh Fitzgerald, Associate Extension Professor, Agriculture, UMaine Extension Kennebec County; Kate Garland, Horticultural Professional, UMaine Extension Penobscot County; Pamela Hargest, Horticulture Professional, UMaine Extension Cumberland County; Kathy Hopkins, Extension Educator, UMaine Extension Somerset County; Tori Jackson, Extension Educator: Agriculture and Natural Resources, Rebecca Long, Agriculture and Food System Professional, Oxford County; UMaine Extension Androscoggin and Sagadahoc Counties; Marjorie Peronto, Extension Educator, UMaine Extension Hancock and Washington Counties; Elizabeth Stanley, Horticulture Community Education Assistant, UMaine Extension Knox, Lincoln, and Waldo Counties; Frank Wertheim, Extension Educator, Agriculture/Horticulture, UMaine Extension York County; and Mary Wicklund, Home Horticulture Coordinator, UMaine Extension Cumberland County.

Q. This spring I purchased eight Boyne and eight Killarney raspberry bare canes from a local nursery. They appear to be doing just fine, looking healthy and yielding berries this first year. I have them supported by your recommended “T” trellis system. I have reviewed your #2066 bulletin, Growing Raspberries and Blackberries. What do you suggest for ground winter protection for the plants?

A. Allowing the plants to yield fruit the first year may have reduced the development of roots and new canes. If the plants look healthy and if you mulched them when you planted them, there is nothing more to do to protect them. If you didn’t mulch at planting you could apply a mulch now using materials suggested in the fact sheet. I would caution that you should NOT use compost at this time, since compost provides nutrients and the plants need to go into dormancy this fall.

Q. We live in western Maine and have a good deal of acorn caps left over from the acorns that drop from our oak trees in our front yard. Is it possible that the caps may be of some use possibly in the compost or other uses?

A. This is a good mast year like we had in 2017. The acorns will be well utilized by wildlife as this article from UNH explains.

Acorns and their caps can be raked up and put in your home compost as a source of carbon. Alternate layers of carbon (acorn caps, straw, wood chips, shavings, dried stalks) with sources of nitrogen (kitchen scraps, grass clippings, coffee grounds, etc.) to start the decomposition process.  If you’d prefer to chop them up, flail them with a weed-whacker in a large trug. Be sure to wear eye protection and long sleeves when you do this. They can also be piled up and mowed with a mulching mower.

If there are large amounts of whole acorns, they can also be tossed into weakly forested or logged areas, and fed to pigs (but not horses).

And there are a lot of crafty things that can be made with acorns, too.

Q. How late is too late to plant Astilbe? My garden client’s Astilbe order is back-ordered until mid October.

A. Yes, mid-October is a bit late, but you’re in central-southern Maine, so these options might work:

  • Have the nursery hold the order until spring planting time.
  • Hold the plants in a nursery garden: Spread the pots 6″ apart in a flat protected area and carefully pile generous amounts of bark mulch below and around the group of plants, being sure the crowns are not covered. Water well but don’t keep them wet. After Thanksgiving, cover them lightly with balsam fir boughs to keep the ground frozen and prevent heaving. If the area is not a low spot that collects water, they should be OK in the spring.
  • Plant them at the job site: Prepare the soil now, being sure there’s no added fertilizer in the planting holes. The holes should be wide but not deep. Amend the soil with no more than 25% bagged compost (not composted manure), mixed well into the native soil. Remove the plants from the pot and gently spread the roots into the planting hole with the soil. Be careful they’re not planted too deeply with the crowns too low (or too high). Mulch with 2-3″ of bark mulch, being careful not to cover the crown. Water well but don’t saturate too often. After Thanksgiving, cover the plants lightly with balsam fir boughs to keep the ground frozen and prevent heaving.

We had a lot of calls about dying astilbe this season. They like cool, moist soil in part shade, the heat and drought was hard on them. Here’s some general information about growing astilbe in the Cornell Growing Guides.

New grassQ. In March of 2020 we had a service spray pre-emergent on our front lawn, so all summer it was completely bare. On August 10, we tilled the ground and re-seeded with a mixture of grass seeds recommended to be best for Maine. Would you please identify this grass that seems predominantly what is now growing, my concern is that it is crab grass taking over again.

A. I suspect you might be on the right track with your grass identification, but it’s tough to say for sure without seeing the seed heads. It makes sense that you’re noticing a flush of new seedlings after tilling the area because there is likely a collection of seeds resting in your soil seed bank just waiting for the moment when they are exposed to the right conditions to germinate. Encouraging dense, healthy turf is probably the most important step to managing crabgrass. This involves testing your soil to determine what steps might need to be taken to adjust pH or nutrient levels to optimize soil conditions, keeping the mower blade at the highest setting and watering deeply during dry spells, but only once or twice a week.

In small settings, hand pulling before the plants set seed is a good strategy. I wouldn’t recommend applying herbicides on what has emerged this late in the season. Try the preemergent again next spring when the forsythia are blooming and wait until August to apply another round of grass seed. This time, avoid doing a full till of the area. Instead, lightly sprinkle some compost over the area being seeded, sow seed, top with chopped straw and use a roller to ensure good seed to soil contact. Water newly seeded areas deeply 1-2 times a week.

Q. My husband and I are building a new home in Kennebunkport (Cape Porpoise). We are finally getting close to completion and are wondering about seeding the lawn. Should we wait until spring? Or will the grass have time to grown and harden off before winter so that it will survive? Is there a specific type of grass that you think would be best?

A. Because you’re in southern Maine, you can do this through the whole month of September. In fact, it will be very important to stabilize the soil to prevent erosion and runoff before hard winter rains. If you’re near the coast, lake or river, be very careful with fertilizers since they’re a major source of pollutants.

We have a lot of very good information about preparing and establishing home lawns (and renovating existing ones) in the Lawn section of our Yard & Garden website.  The site also has information you may want later about Plants for the Maine Landscape.

You’ll notice that we recommend a soil test. You can go ahead and do the soil prep and test the soil later if you’re short on time.  Soil pH is particularly important for a healthy lawn, but you can adjust it later if needed. Let me know if you’d like some test kits sent to you.

Q. I have several Baptisia australis plants which I have sort of been given freedom to do whatever by my landlord. Should they be left full grown to overwinter or should they be cut down? They are big bushes which all seem healthy although I have clipped off the seed pods.

A. If the plants are well-established, they don’t need any special treatment before winter. If they look somewhat messy right now, it’s fine to cut the herbaceous stalks to about 4-6″. Leaving a bit of a stalk will let people know where to avoid stepping. It’s also a good time to do any weeding or mulching around the plant.

These plants are pretty care-free in terms of fertility and maintenance, but staking might be an option (similar to peonies) before they get too big in early summer. Some more formal gardeners will trim the plant after flowering to keep it from getting rangy looking. (This eliminates the pods, which some people like.)

Here’s more about Baptisia from the Cornell Growing Guides and Missouri Botanical Gardens.

Q. I would like to plant hard neck garlic in Southern Maine. Can I plant garlic in this area, will it survive? If yes, when should I plant it.

A. Garlic is a great crop for Maine gardens. In southern Maine, you’ll want to wait until late October to plant garlic. Here’s a bulletin that covers all the details you need, Growing Hardneck Garlic in Your Maine Garden.

Q. We are planting oats as a cover crop for our small vegetable garden and wonder how much we’ll need for 300 square feet?

A. For 300 sq. ft you need a little over 0.8 pound of oats. We have a cover crops and green manure website that you may be interested in.

Also, we have a monthly garden email that we send out. If you would like to be added to the list let me know. It is called the Central Maine Garden Newsletter.

Q. Can I sow poppy seeds in the fall in Waldo County?

A. Poppies throw their seed naturally after the flowers go by, and the pods dry and break. They land on the soil near the parent plant or are dispersed by birds, insects and small mammals. A very small percentage of seeds survive to flower. That’s probably why they produce so much.

Mimicking this natural cycle, poppy seeds can be sown successfully in late summer into early fall. Making a well-prepared seedbed raises their chances of survival. They can also be planted in the spring about 5 weeks before the last frost. Most poppy seeds need to be stratified (chilled) and also need some light to germinate, so prepare the seedbed, sprinkle the seed, and gently use the back of a spring rake to push them slightly into the surface of the soil.

Here’s information about growing and planting different types of poppies from Botanical Interests.

Q. What are the best flowering bushes to plant in the fall in Maine?

A. Except for some fine-rooted spring-flowering plants like rhododendron and azaleas, (plus eastern hemlock and Japanese maple), most plants will do well if planted in September in time for their roots to become established. Here are some guidelines:

  • Do some research about the location you want to plant in. What’s the soil type, soil moisture, sunlight, space, wind exposure, etc.? If you have a special plant in mind, do you need to order a soil test kit?
  • Do some research about which plants will match the space and conditions in the location.
  • What time of year do you want flowers? Do you want spring flowering shrubs like lilacs? Late summer flowers like hydrangeas?
  • Does the foliage matter? There are plants like ninebark and weigela with cultivars bred for wonderful colors and textures.
  • Once you’ve narrowed down the options and have a list, choose a nursery to visit. Many have excellent websites with inventory and descriptions of the plants.
  • At the nursery, choose plants that have healthy-looking leaves and are well-rooted but not pot-bound or spiraled inside of the pot. You can ask an employee to help you gently pull the plant out of the pot to inspect the roots.

There are lots of excellent books about hardy trees and shrubs for the Northeast. Also books about gardening in general which include flowering shrubs. Our website has a number of lists in the section called Plants for the Maine Landscape, including many native species and links to other sites like Maine Audubon’s new native plant database that tells you which birds are supported by each species.

Survival of your new shrub through the winter is critical, so be sure to follow the planting instructions in this fact sheet: Selecting, Planting and Caring for Trees and Shrubs in the Maine Landscape.

Q. Our corn crop was disappointing. We could feel that ears weren’t filling out very well, so we waited a little longer than usual. When we picked them, they were starchy and not very sweet. The few ears that were sweet were about 3/4 filled out. What might have caused this?

A. There may be several things that happened to your corn to cause the ear not to completely develop. We did have very hot, dry weather and if that was during the time that your plants were silking, that can reduce the pollination of the ears. Irrigating and incorporating more organic matter into the soil to help hold soil moisture can help. 

Not enough nutrients, nitrogen in particular. Corn is a big user of nitrogen and if there isn’t enough at the time the ear is filling, it can prevent the ear from completely developing. Manure this fall or compost in the spring can provide nutrients or a garden fertilizer that has nitrogen in it. 

Corn is wind pollinated so if the corn is planted in a single row and not a block of four or more rows, pollination may not have happened. Insects that feed on the silk just before pollination can prevent pollination from happening. 

Our colleagues from University of New Hampshire have a factsheet on growing sweet corn in the home garden that may be of interest. 

Q. I am building in a three acre piece of land that is covered in poison ivy. The land is surrounded by forest, but is basically an open field. What would be my best approach to eradicating it from the field areas, keeping in mind that children and animals will be playing there?

A. The first thing is to be sure you have Poison Ivy. Leave of three- let-it-be is an old adage, but there are some plants that have three leaves and are not poison ivy. Other things to look at are if the leaves are shiny, if they have small nondescript flowers, or if there are white berries present. 

The Maine Dept of Ag has a nice website on poison ivy identification and control

It sounds like your infestation is too much for hand pulling and you may have to look at herbicides. Our colleagues at Clemson University have a nice publication on poison ivy control (PDF) that outlines how to use either glyphosate, 2,4,D Amine, or Triclopyr. Once you have a frost, the plants are no longer susceptible to the herbicides. 

Q. I live in Auburn, Maine. I was wondering if you could tell me what I can grow in my back yard for small trees and shrubs? I have Emerald Green Arborvitae, that I put in four months ago, so far so good. Today a Dappled Willow Flamingo Standard, but not sure if they will do good. In the spring there is lots of water, there is clay, and lots of sun.

A. Based on your site description (sunny with clay soils), I recommend checking out these plant lists for inspiration: 

Many great plants will perform well in your landscape. It’s tough to say what will visually work well without seeing your space, but here are some of my personal favorites: 

  • Sambucus nigra (elderberry)
  • Spirea tomentosa (steeplebush)
  • Viburnum nudum (witherrod)
  • Monarda didyma (bee balm)
  • Eutrochium purpureum (Joe Pye Weed)
  • Filipendula rubra (Queen of the Prairie). 

Starting with smaller plant material can often help you get better establishment in the long-run and will save you money. Local nurseries may have some smaller potted plants, but you may also want to consider ordering bare-root trees and shrubs this winter to plant in the spring.

Q. I have a small raised bed vegetable garden maintenance business and I have a question about soil testing. My biggest problem seems to be nitrogen. I’m attempting to amend but based on my “Luster Leaf Rapitest Soil Test Kit” I am consistently in the depleted to deficient range. — I am considering using a nitrogen test strip product. I don’t need precise measurement: I only need something like 3 levels (low, med and high). Are the strips reasonably accurate for this purpose? Do you have any other recommendations?

A. Nitrogen is a very transient nutrient in the soil. It is hard to use an over the counter test kit and get accurate results. The reagents in the test kit may be old or calibrated. Our soil test lab does offer nitrogen testing, but you must not dry the soil samples. You may want to test just one bed to see what the lab indicates for nitrogen levels. You can use the comprehensive test. Order a test kit here.  

For small raised beds a simple indicator of depletion of soil nitrogen is the leaves turning yellow. There may be a number of things happening in the beds to make the nitrogen less available. We do have a factsheet on Nitrogen that was written for potato production, but can give you more information on how it is depleted in the soils. 

If these raised beds were just formed this year and organic matter was used that had not composted very long the soil bacteria may be taking up the nitrogen. 

Lilac leaf, frontQ. Leaves on a Abraham Lincoln Lilac planted this spring have quickly developed spotting on the leaves. Has spread to most of the leaves in a few days. Can you identify the problem and suggest a solution?

A. I checked with Dr. Alicyn Smart, our plant pathologist and she says a “fungal disease anthracnose is to blame. The only other disease that would cause this is a bacterial infection but I have yet to recover it here. Here is a factsheet on it, Anthracnose of Trees and Shrubs (PDF). Raking the leaves in the fall is recommended and disposing of them via compost or trash. Depending on when the symptoms started it might be worth using a potential year warranty if she went to a reputable place.”

Q. I live on the east end of Portland and I know I have lead in my soil. I have apple, peach trees and grapes. I was wondering if the fruit would contain the lead as well? If yes, is there a safe amount that we can eat?

A. Generally plants do not absorb lead into their tissues, but the dust from garden soil contaminated with lead is at risk of settling on plants and fruits that we may want to eat. 

The first thing to do is do a soil test to see what level of lead there is in your orchard. Here is our Know Your Garden Soil that discusses how to do the soil test. The UMaine Soil Test Lab does a lead screen on all garden soils, so you can get the idea of how concerning your lead level is. You can ask for a soil test kit here.

Once you know the lead level you can refer to our Lead in Your Soil factsheet for things you can do to mitigate a high lead level in your soil. Please note that children less than six years old are at special risk of lead poisoning. If you have children under six who have played out in this orchard area and the soils are high in lead, you should have them checked for lead level in their blood.

Grapes grown on a trellis and tree fruits generally don’t uptake lead from the soil, but soil dust that blows up onto the fruit should be washed off before using. 

hemp-nettleQ. Can you tell me what this, I’m guessing weed, is? It showed up last year in a lacking piece of lawn, disappeared over winter and this summer started again. (I live in Standish.) It has taken off like wildfire. I’ve been pulling it by hand but there is a LOT of it.

A. It looks like Hemp-Nettle. It’s an annual that has reseeded itself. If this area is supposed to be part of the lawn, you can apply lime and fertilizer by soil test recommendations, reseed with grass seed, and plan to mow it regularly. The regular mowing will control this weed. It grows since there is no grass competing with it. 

Q. This question is about impatiens and phlox that have been denuded of blossoms and foliage. Only stems remain, and I’m wondering whether this is characteristic of deer damage, or something else?

A. Without seeing pictures of the damage, it sounds very suspicious that it is deer damage. If you have any soft soil in the area, you may be able to see footprints.

Next year you may be able to put up some fencing like lightweight netting or monofilament fishing line attached to stakes around your flowers. There are deer repellents that can be sprayed on flowers, but sometimes they can damage the flower petals. As a last resort, you could consider planting different flowers. We do have a website that lists Plants Usually Not Preferred by Deer.

 Q. What should I add to my soil for a road side garden to counter act the winter salt?

A. I’m not sure if you are referring to a landscape planting or a vegetable garden. I am thinking you have a landscape planting within 15 feet of a road that gets salt during the winter. This is the area that can be impacted by salt.

Our colleagues at Rutgers developed a nice factsheet on the Impact of Road Salt on Adjacent Vegetation.

In addition to how salt impacts plants, this factsheet includes options to try to mitigate the damage.

First is try to prevent damage, by using barriers or screens to protect plants. Evergreens can be treated with anti desiccants. Incorporation of Gypsum within the dripline of shrubs and trees at the rate of 50 lbs./100 sq.ft. can help if the soil can be disturbed to a depth of 6 inches. The factsheet includes a list of plants that are more salt tolerant that you may want to consider replacing plants that are affected by salt.

A soil test might help you determine if there are nutrients that are deficient in your garden area. You can order a soil test kit online.

Q. We have to do an annual mow to keep the field open but I don’t know the best time to do that mow. Is there a mowing schedule you would recommend? A time when the monarch migration is over? I was advised once to mow only half of the field each year.

A. Our colleagues at the Connecticut Agriculture Research Station have a factsheet on Proper Timing to Mow Native Plant Meadows Can Protect Pollinator Habitat (PDF). They are recommending to wait until after our first killing frost to mow our fields. 

Did you know that UMaine Extension just launched a Pollinator-Friendly Garden Certification program? I bet you are doing a lot of the activities that they discuss. You should consider applying for this certificate. 

Q. I have been reading a lot about aerated compost teas and how they can be used on the foliage to help protect against things like fungus and insects. Do you agree with these type of statements? If so, could application on my tomato plants help with leaf spot?

A. The short answer to your question is no. There is no scientific research that indicates or supports that compost tea is effective controlling fungus diseases or insects.

Aerated compost tea has been widely touted by gardeners as a cure for plant diseases but is largely anecdotal and not supported by peer reviewed research. Dr. Milner, USDA, did work on strawberry fungal diseases many years ago but had very limited success.  Products that are used to prevent or kill diseases or insects need to be registered as a pesticide. Compost tea is not registered.

I would suggest removing the lower of the tomatoes below the first fruit cluster. This will help prevent soil fungal spores from splashing onto the leaves and continue to remove leaves as the fruit ripens. This will slow down the spread of septoria leaf spot. Here is a factsheet on Septoria Leaf Spot of Tomato.

Tomato with spotsQ.Our tomatoes have white spots in them and we were wondering if you could tell us what it is, what is causing it, and what to do about it.

A. Clay Kirby, our insect diagnostician feels this could be stink bug feeding damage. Especially since we had a dry summer.  Weed management helps eliminate hiding places and spring food sources for stink bugs.  Spinosad and pyrethrins are two organic options applied in July for nymph management. Adults stink bugs are difficult to control with anything.

Q. I planted an acre of Buckwheat this year to help improve my clay soil here in Kennebec County. But also to give my honey bees an additional source of nectar and pollen. I’ve irrigated as best I could due to the ongoing drought and wanted to know if nectar bearing flowers/plants stop producing nectar when its dry and start producing again after we get rain or a good shower? Can they stop and start or once the nectar stops flowing that’s it for the year?

I can see when bees are successfully collecting pollen but I can’t tell when the bees are collecting nectar.

A. As long as the flowers are opening there is nectar being produced. If the plants are so dry that they stop flowering, then the nectar stops. Buckwheat can recover from dry, hot weather and start reblooming. From what I have read, Buckwheat does best with clear days and cool nights. High temperatures over 85 degrees can cause flowers to abort. A word of caution, if you let the buckwheat continue to bloom, the first flowers that opened will be pollinated and will start to set seed. The plant can have mature seeds dropping as well as new flowers opening. It can result in the buckwheat becoming a weed in your garden. 

Our colleagues from Wisconsin and Minnesota have a factsheet called Buckwheat that has a lot of other interesting information on the crop.

To learn more about bees visiting buckwheat for pollen and nectar, here is a research article on that topic (PDF) that really goes into depth on the subject. 

Blue wormQ. What is this worm?

A. It is a beautiful blue looking caterpillar. Our insect diagnostician says it is a Red-humped Oakworm. 

Q. Is using nursery-grade landscape fabric considered safe for organic gardens?

A. Is your garden a vegetable garden or an ornamental garden?

As far as safety is concerned, geotextiles don’t “leach” any harmful chemicals into the soil unless you purchase the kind that’s imbibed with an herbicide.

For commercial organic growers, The Maine Organic Farmers and Gardeners Association (MOFGA) stipulates on page 13 of their manual (PDF) that synthetic mulches must be taken up at the end of the growing season.

For home and commercial gardeners, landscape fabric can be used successfully for growing plants like tomatoes, peppers and other crops that like warm soil.

In the landscape, weed barriers can become an issue over time. Here’s an interesting article (PDF) by Linda Chalker-Scott of Washington State University.

Q. What is on the leaves of my native black willow? The three attached photos show three different situations on the same black willows.

A. You have several things going on with your willow. I checked with our plant pathologist she agreed with me:

  • Picture 5619 looks like a fungal leaf spot.
  • Picture 5621 looks like willow rust, but we had trouble zooming in on the leaf. It could be feeding from non-eriophyid mites.
  • Picture 5623 is willow gall, caused by eriophyid mites.

To try to reduce the incidence of this next year, this fall rake up the leaves and dispose of them at a landfill. Do not compost.

Q. I bought a new home In Falmouth last October. The first thing I had done was having the new garden plowed. I planted garlic and it turned out well. This summer I’ve had veggies and now as things wind down I’ve spread straw and a couple inches of composted cow manure. Should I let the straw/manure mix rest all winter, or should it be tilled or harrowed?

A. In order to assure proper breakdown of any potential harmful microbes in the manure it should be incorporated into the soil this fall. Here is a link to our Guidelines for Using Manure on Vegetable Gardens.

Q. Last year I planted some short-season watermelons, such as Sugar Baby and Blacktail Mountain. I waited until the tendril opposite the attachment point was brown and the melon had a large bright yellow spot before I picked it. All I had were white and pink inside. I planted the same varieties this year. Several days ago I picked a Sugar Baby. It had the brown tendril and a large bright yellow spot. Again, the flesh was white and pink inside. It was beginning to be sweet. I would appreciate some guidance on when to pick them.

A. Oh no, you are doing all the right things. It is aggravating when it doesn’t work just right. The tendril needs to be brown and dry or crispy. The only other “test” you could try is the “Thump test” rap on the melon with your knuckle to see if there is a deep thump that sounds like the melon is hollow. 

Here is a website from eXtension that covers all the signs a watermelon grower can use to determine when the melon is ready to harvest. 

Stink bugQ. What type of beetle is this? Friend or foe? Fast and sneaky in that they dodge into first place they can find to hide.

A. You have an excellent picture of a stink bug larvae. Here is our factsheet on stink bugs.

Q. I live in Yarmouth and would like to grow Echium pininana in a couple borders. I’m having a hard time finding seed in the US but can purchase from the UK. Considered invasive in some areas. Is it safe to grow in my location?

A. This plant, Echium pininana is not hardy enough for zone 5b in Yarmouth, where winter temperatures are frequently below freezing. In the much warmer (frost-free) temperatures and soil conditions of the Canary Islands, this short-lived perennial takes about three years to mature, blooms and usually dies. That said, in the grand era of botanical exploration, these plants were brought to much colder climates like southern England where they were grown and protected in the cold season. Further north, they were kept in heated conservatories and brought out on display in the summer to impress guests. (It’s a really striking plant.)  In parts of California coast, the plant has become invasive. I’m not sure if this is helpful but feel free to bookmark our Garden & Yard website for lists of plants that do well in Maine.

Green butternut squashQ. I have been growing winter squash for many years now and have never seen one that looks like the one in the photo. I have butternut and buttercup growing in the same area and a few of the butternut are totally dark green just like the buttercup.
Have you ever experienced this before? If I save some of the seeds will I get green butternut squash next year?

A. A lot of people ask about the result of two similar types of plants that cross pollinate and the resulting fruit. 

It does look like you have a cross between a butternut and some other type of vine crop from the same plant family. The plant that is growing this fruit this year is from a plant that got crossed with something last year. If you save the seeds from this fruit, it will have crossed again with the buttercup or some other squash species growing in your garden now, and would produce something different next year. Still a squash, but not sure what type. 

Or put another way, the flesh of the fruit (squash) is determined by the genetics of the seed that you planted in the spring. The seeds in that plant that you harvest this fall will have the genetic variation from the cross pollination last spring. Iowa State University has a nice factsheet on Cross-pollination Between Vine Crops that may be of interest to you. 

Q. Due to the yearly droughts I need to replace the asters in my flower garden. I currently have asters (purple dome), asclepias tuberosa (butterfly week) and yarrow. The butterfly weed is thriving with new shoots throughout the garden bed. The yarrow is not thriving but it’s alive. I’d like to replace the asters with Russian sage (perovskia atriplicifolia.) Is there a better choice for visual balance and for pollinators? I welcome all comments.

Also, regarding my vegetable garden. I got a soil test this year and followed the recommendations but the harvest is not what it used to be. I was thinking that, this fall, I should add a layer of manure and a top layer of compost. Please advise.

A. I can answer your last question first. This has been a very hard year for gardeners who did not irrigate their gardens. Adding manure and compost this fall and tilling in will help the water holding capacity of your garden. In June my colleagues released a video on How to Water Your Garden that may be helpful. If your garden soil was on the acidic side and you added lime, it can take over a year for the lime to work at neutralizing the soil.

As far as suggestions for alternate plants to replace your asters, we just released a new Plants for Pollinator Gardens a few days ago. We also have developed a new Pollinator-Friendly Garden Certification that you may be interested in too. 

Q. I live in Kennebunkport, approximately zone five. Why don’t I have many or any blooms on my hydrangeas this summer?

A. Here are links to a couple of research based articles on hydrangeas not blooming that may help. 

Q. Is Queen Anne’s Lace poisonous? In particular, I am wondering about Dara.

A. Queen Anne’s Lace, Dacus carota and the variety Dara which you mention are considered of low toxicity and would have to be ingested in large quantities to make someone sick. The sap can cause a mild skin rash if someone is exposed to it in sunlight. Here is a link to a profile of Queen Anne’s Lace, Dacus carota. Scroll to the bottom where toxicity is discussed. 

Q. I am going to purchase a drip irrigation system and wondered if there is a brand you would recommend (or maybe one you would advise to avoid)?

A. Unfortunately the university does not recommend or endorse specific commercial products or brands. There are many good drip systems in the marketplace, both in garden centers and via online suppliers. Here are links to a UMaine Extension fact sheet on Drip Irrigation and another bulletin, Drip Irrigation for Home Gardens from Colorado State University Extension.

ColtsfootQ. An unusual plant is coming up along the road. It’s in and next to a ditch/intermittent small stream (currently dry) with some shade. I have noticed it in only one spot there so far. If it is an exotic invasive I would like to stop it in its tracks. The shoot pulls up easily. It is difficult to tell whether it is spreading by rhizome or from seed, but more likely rhizome as the root seems to break off. The leaves are about five inches long.

A. It looks like you have a plant called Coltsfoot. The Maine Natural Area program lists it as a level 3 invasive, with habitat specific threats.

Here is their page, Advisory List of Invasive Plants-2019, where you can search for “Coltsfoot” that links to this page for more information

It is an interesting plant in that the yellow flowers bloom first in the springtime, then the leaves come out.

American Hog-peanutQ. My neighbor and I have wildflower gardens side-by-side. My side is filled with the plant in the attached photos, which I think is Hog’s Peanut. My neighbor is convinced it is poison ivy, which she is very allergic to (I am as well- but no reaction to this plant yet), and wants to spray the border of our gardens with glyphosates to kill it. Could you help us out with a positive ID? I’m happy to take it out if it really is poison ivy, but don’t want to be using pesticides if they’re not needed.

A. You are right, that’s not poison ivy, Toxicodendron radicans, but American Hog-Peanut Amphicarpaea bracteata.

This article, American Hog-peanut,  from the University of Wisconsin goes into some detail about the plant and may help you decide what to do.

If you choose to use pesticides, always follow label directions.

Virginia creeperQ. I have a vine growing that I wonder if you could help identify. I would like to ask if there is anything to be concerned about with this plant? I am trying to decide whether to remove it or leave it to flourish.

A. It looks like you have Virginia Creeper or Woodbine growing in your yard. It is not an invasive species, but it can grow quite aggressively.

Some people enjoy their leaves in the fall when they turn bright red. It does have fruit that wildlife will eat. 

We do include it as a vine that can be planted successfully in very dry and shady soils

Q. Do you know where you can buy dragonfly nymphs for the next season? I live in Old Orchard Beach.

A. According to biologist Philip DeMaynadier from the Maine Dept of Inland Fisheries and Wildlife in this article from the Bangor Daily News:

“Mainers should also resist the urge to import dragonfly nymphs from biological supply companies to manage mosquitoes, which deMaynadier said has been a common practice for some towns and land trusts in the southern part of the state, as well as for private landowners, for the last 40 years. These practices can bring invasive species into Maine, especially considering that the biological supply companies are all based out-of-state and provide species of Odonata that are not native to Maine.

“We don’t know what other consequences when you introduce high quantities of a top predator into the state,” deMaynadier said. “That’s my greatest concern.”

Plus, importing dragonflies doesn’t work to control mosquitoes, according to a study deMaynadier co-authored in 2020 using baby pools filled with dragonfly nymphs in a controlled forest setting.

“We found no significant effect of dragonfly nymphal predation on mosquito larvae,” deMaynadier said. “Other natural predators were dipping into those pools just as much as the dragonflies.”

Q. I have an abundance of green beans this year, is it possible to let the last of the crop grow and dry on the vine and use the bean seeds for baked beans?

A. You can use beans from your green bean plants as dry beans, as long as they have dried properly. If the beans or pods become moldy during the drying process, you should not use them. One of our food safety specialists suggests this article: Mature & Dry Green Beans. It’s not an Extension site, but she felt it provided some useful guidance. Remember that the green bean varieties were bred for fresh eating. You might notice some differences in flavor, texture, or quality compared to typical dry bean varieties.

palthis angulalisQ. I have a worm/larva that is eating my Ninebark. It is sort of a pinkish-orange-brown. It changes slightly as it “ages”. At one point it has an orange head. It seems to build a web and folds the leaf in on itself. I would like to know what this is and how to get rid of it.

A. Our insect diagnostican says that: “The caterpillars on your ninebark look like the Tufted Thyatirid caterpillar, although there are at least two very similar looking species. Handpicking these off the plants seems to be the best approach if you want to avoid pesticides.”  

Here is a link to the Tufted Thyatitid Moth page. 

mowed half acreQ. I have about a half-acre of cleared land below the house, that was cleared maybe 8-10 years ago and has been badly neglected. I’ve had it mowed nearly every year so there are no trees growing up, but the soil is quite thin to the point of there being some bare spots. There is a little grass, a lot of goldenrod, blackberry, and other weeds. I’d like to work on moving it towards being more pasture than wasteland! How should I start? Do I have to have someone plow, or bring in more soil?

A. It sounds like you don’t have an issue with rocks or stumps in the field.  
It would be good to think about what animal(s) you would be planning to pasture in your 1/2 acre area. It will only support up to 500 pounds of livestock (a small pony, a couple of sheep or goats, some chickens.) 
We do have a factsheet, “This Old Hayfield” that has information on improving a neglected hayfield or pasture. It recommends: 

  1. Doing a soil test.
  2. Mowing the field.
  3. Adjusting the pH with lime if acid. Add other nutrients if needed.
  4. If the field is smooth enough to mow, mow at least three times a year, leaving at least 3 inches of grass.  This regular mowing will reduce the incidence of annual weeds.
  5. Consider frost seeding or no-till seeding to get more desirable plants in the area.
  6. After a few years of this treatment, the grass and clover will start to take over the field and the weeds will regress. 

Q. I have a property on Flying Pond in Vienna. After much work, I was able to clear my waterfront of poison ivy. Ultimately, this has led to bare soil. The area possesses significant trees, however there is not a significant amount of trees.

My objectives are two fold. I would like to “reforest” the buffer zone along the shoreline to 1) halt erosion on the sloped land leading to the water and 2) installing plantings that absorb excess nutrients that come downhill from a private camp road (phosphates, etc..).

The area is shaded and I believe the soil is acidic. I intend to employ a version of the Miyawaki method to cultivate the next generation of trees to take over the shorefront as the older ones die off and create a healthy undergrowth of bushes. Could anyone recommend a list of native trees, shrubs and groundcover that can handle the low light conditions mentioned above? Any aid is greatly appreciated.

A. At the following website, The Buffer Handbook Plant List (PDF) you will find a list of plants for vegetative buffers in Maine. There are quick reference charts that indicate each plant’s sun/shade and soil drainage preference, along with mature size range, and native status. Thinking about your site, it seems perfect for some of our native viburnums (Viburnum lentago, V. alnifolium, V. cassinoides) and native dogwoods (Cornus racemosa, C. alternifolia), but when you look at the list you’ll see that you have many other plants to choose from.

PumpkinQ. My daughter, who lives in the Farmington, Maine area, is disappointed and wondering why her pumpkins are already starting to turn orange in mid-August. Our research has yielded confusing results because some articles say to remove the mature pumpkins from the vine to allow for more flowers, thus more pumpkins, and other articles say to leave it on the vine and it will do well. Her idea was to have pumpkins for the Halloween season, so we are puzzled by this premature ripening. Should she pick them as soon as they are completely ripe, or leave them on the vine for as long as possible? How long will they last if kept in a dark, cool space? She does not know what variety of pumpkin they are, but her pumpkin patch has done very well so far this year. Thank you for any advice you can provide.

A. In hot years, pumpkins can ripen earlier than you might otherwise expect. If possible, leave the fruit on the vines until they are fully ripe. That means their fully orange, the rinds are tough, and the handles (stem) are solid. As long as there is good leaf cover, you can leave the fruit in the garden. However, they are more susceptible to pests there, so you may want to move them out of the garden. If there is not good leaf cover, then the fruit are susceptible to sunscald, which will ruin their storage potential. If possible, cure the pumpkins at 80-85 degrees for 10-14 days, as that will increase their storage life. You may want to check out this UMaine Extension video about pumpkin harvest and storage.  

Q. Need recommendation for the best time to plant determinate tomato seeds for transplanting into containers, we are located in Phippsburg, Maine.

A. In our climate, we need to start all types of tomatoes indoors and then transplant them outside after risk of frost has passed. So, your friend will need an estimate of when their typical last frost in the spring is. This map from the Northeast Regional Climate Center may help. Tomato seedlings are usually started 6-8 weeks before that last expected frost date. Supplemental lighting and a heat mat can help get the seedlings up and going. More information about starting seeds can be found in this UMaine Extension fact sheet, Starting Seeds at Home.

Lilac treeQ. My Miss Kim lilac has experienced sudden die back. It is not currently affecting the whole plant, just certain branches. I don’t see any insects. Should I immediately cut out the branches with dead or dying leaves?

A. There aren’t many insects that attack lilacs except lilac borers, which usually go after larger trunks of syringa vulgaris. (Their large trunks have flakey bark, unlike Miss Kim.)  It would be good to inspect for any trunk damage, even cut off a branch and see if there are signs of borers inside.

In general, it looks like there was some sort of sudden damage to the plant. From your first photo, it looks like there are two lilacs. One normal and one damaged? Are any other plants showing damage?

If there are two, can you inspect the damaged one and compare it to the other to see if there’s any girdling of the bark? Rabbits, porcupines and voles can sometimes do this at or above the soil line. (Though voles are more likely to work under the snow in the winter.) Is the bark damaged by built up bark mulch around the base of the trunk? This can sometimes rot the bark and also bury the roots so they don’t get enough oxygen.

The second possibility is root damage. A large infestation of chipmunks can undermine roots, especially in sandy soil. Has there been any chemicals near the roots? Too much fertilizer? (Which are salts.) Was a bucket with soap, bleach, or ammonia from window or car washing emptied there by mistake? Is there a dryer vent near the base of the plant? Any other source of heat? And lastly, has the plant received adequate water during this drought? Once a week (deeply) should be fine for most woody plants in the curtain drain area, which in new houses is often filled with dead sand (and drains very quickly).

There are a lot of ways plants can be damaged, so it requires a bit of sleuthing. We’ll eliminate some of the possibilities and hopefully get to the bottom of it.

damaged cauliflowerQ. My cauliflower have been blanched with leaves tied over heads and the heads have a brown rot. What is causing this?

A. I checked in with our Extension Plant Pathologist, Alicyn Smart, and she does not think it is a bacterial soft rot such as Erwinia. She states bacterial soft rot would appear more water soaked and would give off a “smelly feet” odor that is quite distinct and which people usually comment on. She states that “the heat is causing plants to be susceptible to weaker pathogens getting a grip on the plant that they usually are not able to do so. She leans towards it being caused by the heat and thus is more an “environmental cause” that weakens the head tissue and makes it susceptible to microbes that are causing the browning you would not normally notice. Unfortunately there is not anything you can or could do to prevent it. Hopefully with cooling weather future heads will not see the development of this issue.

Q. We are trying to figure out what animal is eating the inside of green and ripening tomatoes in our community garden. This has happened during drought periods in the past so we believe it provides a source of moisture. Almost every plot with tomatoes has been affected.

A. There are a couple of pests that come to mind that could be causing this problem. One is birds.  They may be pecking into the fruit for the moisture. When I have seen this on green fruit, the fruit are left like empty hulls, with the pulp and seeds missing. Chipmunks, squirrels, and even turtles will cause chewing damage on tomatoes as well. Another possibility is the tomato fruit worm, which will burrow into the fruit. Depending on the timing, you may be able to find the caterpillar still in there. This is the same insect as the corn earworm, but with a different common name. You may have to do some additional detective work and observation to figure just which of these is the problem!  A list of tomato pests can be found in this publication, Tomato Fruit Problems from the Missouri Botanical Garden. 

Q. I have a vining squash plant that self started from our compost site. It flowers profusely. The female blossoms never open, they eventually dry up. I water every morning using a drip hose. I have also given the plant an organic vegetable fertilizer. Any suggestions?

A. I’m not finding solid research-based info about this problem of female flowers not opening. I do see suggestions that stress could be the problem, including high heat and inadequate water. Although you’re watering regularly, sometimes crops need more than we think. Be sure to check the soil moisture a few inches down to be sure the water is infiltrating appropriately. The flowers might also be decaying before they can open. If that’s the case, you would see some discoloration of the petals and/or the flower stalk. Another idea is that there might not be enough sunlight for the plant. Finally, the high organic matter of the compost could be leading to a nutrient imbalance or possibly making a disease problem worse. Feel free to send some pictures of the plant in its location, a closer-up picture of the plant, and close-ups of the flowers that are failing.

Q. Where can I get local ladybugs?

A. This Cornell University Extension Website is helpful to find informative fact sheets about beneficials and has links to insecteraries which sell them. 

If you are looking to release ladybugs in your home garden to control insects such as aphids which may be attacking your garden plants, UMaine Extension generally does not recommend this practice. Beneficial releases of predatory insects such as ladybugs are helpful when released in enclosed structures such as commercial greenhouses where they will tend to stay inside and search for prey. When released outside in the home garden, lady beetles quickly disperse and often do not attack the prey you are hoping to target them for. 

To attract and sustain local populations beneficials to your garden, maintain a wide variety of flowering plants and avoid using any broad spectrum pesticides to control garden pests. Such treatments reduce populations of beneficial predators that are present, and ultimately that allows the harmful insects to multiply unchecked. 

 Q. I am growing peach trees here in Wiscasset, Maine. I have never grown them and I am learning the hard way. Is there a guide book or publication of what to do and when?

A. They can be a challenge, but many home orchardists find the effort worthwhile.

We have a good amount of information for home gardeners:

Feel free to bookmark our Garden & Yard website for more information about gardening in Maine.

Q. My best conifer is dried out at the top and loosing its traditional triangular shape to become an oval. I have tried to treat it for insects, but it continues to dry out at the top. Can you help?

A. My suspicion is that this classic damage to the top is the result of  White Pine Weevil feeding.  If this is the case, you can remedy the problem with corrective pruning. Completely remove the dead top, back to healthy tissue. Then follow these  guidelines:  

Corrective pruning of injured tops should remove all but a single, dominant shoot (one of the smallest) at the topmost healthy whorl. This promotes healing, resumption of vertical growth and straightening of stem form. Corrective pruning may be postponed until the year after weevil injury to ensure that at least one lateral branch survives ice and snow damage or repeated weevil attacks the following year.

close up with rootsQ. This summer, these small shrubs have been growing and spreading everywhere where there is sun. I left them alone at first as I thought they might be a native of some sort and might bloom later in the season. They haven’t bloomed yet though, and I don’t see any evidence of buds at this point or of any seeds indicating a bloom earlier in the season that I might have missed. The stem becomes tough and woody as it grows. This plant obviously has done well in this dry weather. I haven’t been able to identify it. What is it?

A. The plant looks like an aster. As you can see from this list from the Native Plant Trust, it’s a very large genus of plants.

My best guess is Heath American – Aster, Symphyotrichum ericoides. Since it’s not in bloom yet, it’s tricky to know for sure, as most ID books and tools focus on the differences in flowers.

Let me know what you think once it blooms. Asters are great late-flowering plants that sustain pollinators way into late fall.

Q. Do you have any advice about transplanting volunteer seedlings of pagoda dogwood? They are still small, waist high or shorter.

A. Thank you for your question about transplanting a pagoda dogwood seedling. They make a very beautiful small tree that attracts wildlife. Here’s a fact sheet, Native Trees and Shrubs for Maine Landscapes: Pagoda Dogwood (Cornus alternifolia).

Now is not a good time to transplant, since it’s so hot and dry. Transplanting should be done in the cool seasons – ideally in early spring when the seedling is dormant. Possible but still risky is mid-September. The site should be similar to where the seedling came from – shade or dappled shade is where most of these plants thrive. Try to prepare the soil first and make a hole that’s wide but not deep. Add no more than 25% compost to the planting hole, mixing it well with the native soil. Do not use any fertilizer, since you want root growth and not tender new top growth that won’t harden off before winter. On an overcast day, dig the plant up carefully, keeping as much of the roots and soil as possible. Adjust the depth of the hole with soil so it’s not too deep and gently tuck it in. Water gently to remove air pockets, and mulch if possible to keep the roots moist and cool. Do not let the mulch touch the trunk. This plant likes acid soil, so avoid an area that’s been a lawn or vegetable garden. (A soil test would be ideal.) Water the seedling well, but don’t keep it wet, as roots need oxygen. After Thanksgiving, lightly cover the root zone with balsam fir boughs to keep the plant from heaving. In the spring, check to see if the stem is flexible. If it is, it made it through the winter! Be sure to give it water as needed while it establishes itself in its new home.

Q. I’m looking for someone to help eradicate some Japanese knotweed at a small business in Freeport, and my preliminary internet search isn’t turning up much, any ideas?

A. Here is our fact sheet on the plant, its life cycle, with cultural and chemical options for control.

If you want to hire someone to use an herbicide, they’ll need to have a commercial pesticide applicator license. Here’s where you can find a list of licensed applicators. You can search by category descriptions 6a (Right of Way Vegetation Management) or 6b (General Vegetation Management).

Many landscape companies have licensed applicators on staff. Give them a call and ask if they are licensed to do this service. Be sure the applicator is familiar with your property boundaries.

Q. I have a beautiful bunch of blackberries that are starting to ripen. But I’ve noticed that on some of the new growth canes near the very top in the really soft young leaves, they are starting to curl up and inside each place I see a tiny green worm. This activity is more or less ruining the top growth of the new canes. Any ideas?

A. I suspect a leafroller larvae, but could you send a picture of the leaves that are showing symptoms and one showing the larvae inside the leaf?

If there are only a few, you could pick them off and put them in the garbage, do not compost or drop by the plant. 

Q. I am trying to ID a beetle and the best way to get rid of it.

A. Are you able to take a high-resolution digital photograph and send it to us?  We might be able to identify it from a photo. If you can’t get a good photograph, you can follow the instructions here and send a sample directly to UMaine Extenison’s Insect Diagnostic Lab in Orono.  

Q. When should I plant snap peas for a fall crop?

A. Midsummer and fall planting is a great way to get additional production from your garden. These later plantings take longer to mature than spring plantings. The days are shorter, the sunlight is less intense, and the nights are usually cooler. There’s no set rule for estimating the timing, but for snap peas, 70 – 80 days before your first killing frost is a good guideline. Here is a chart from University of Minnesota Extension. University of Nebraska outlines a formula for calculating time to maturity: Days to maturity + # days you hope to harvest the crop + 10 days extra for delayed growth.  So, if you have an early variety (51 days) that you hope to harvest over a week, you would need to plant at least 68 days before the first frost (= 51 days to maturity + 7 days to harvest + 10 days for delayed growth).  

Cucumber leaf
Cucumber leaf

Poison IvyQ. I have two questions. The first is to get your assistance in identifying Poison Ivy.

Second, my cucumber leaves have been horrible this summer. The plants are still producing fairly well however, I am perplexed about the poor quality of the plants themselves. Any ideas? Photos included.

A. The first photo does appear to be poison ivy. Here is a very good fact sheet link to help you identify poison ivy.

The second photo of your cucumber leaf appears to be a bacterial disease called Angular Leaf Spot. Here is a link to a fact sheet on cucumber leaf diseases which includes this disease. Copper fungicides are effective against bacterial disease but it may be too late for this year. Oftentimes this disease is transmitted by cucumber beetles so be on the lookout for them as well. Using a row cover over your crop can exclude cucumber beetles but you have to remove the cover when the plant is flowering so they can be insect pollinated.

Maple saplingQ. I transplanted a maple sapling from our woods three summers ago and it grew quickly. However, this summer, one of the trunks that looked fine at the beginning of the summer gradually turned brown and is now looking dead. What caused it and what to do? Cut that trunk? Leave and hope it regenerates? It doesn’t look diseased just brown.

A. Thanks for your picture, but could you get down close to the ground, pull the grass back a bit to see what is happening to the trunk at the ground level? I suspect someone may be weedwacking close to the saplings and has girtled the trunk of the side that looks dead. Check out the other side to see if there is anything happening at the ground level.

If all looks good with the left side of the plant, cut off the right side as close to the ground as possible without nicking the left side. pull up the grass, by hand and lay down some mulch. Do not let the mulch touch the bark of the tree. This can provide a buffer to get the grass trimmed next to the trunk of a tree without damaging the trunk.

Q. Why did my zucchini plants flower, but produced no fruit? Cukes are profusely flowered but few small fruit.

A. Vine crops are monoecious, meaning they produce male and female flowers. Male flowers come out first and are followed by female flowers that have immature fruit at the base of the flower. 

Cold, damp weather conditions during blooming can slow pollinators from carrying the pollen from the male to the female flowers. 

Lack of bees and other pollinators can reduce fertilization of the female flowers, too. Honeybees have been having a hard time in recent years with disease and parasites. Also, spraying of insecticides during the day and directed at flowering plants can reduce the number of pollinators.

 If you see plenty of female flowers, you can try to pollinate by hand by picking a male flower, and gently rolling it’s pollen onto the stigma of the female flower.

Q. We live in Midcoast Maine on a cove. We have relatively new neighbors who just had nearly 20 poplar trees felled in their yard, deeming them “weak, sick and dying”. (Apparently one did come down in a storm/high winds, not on any structures, so the rest were taken down also as a precaution. I don’t recall if actually sick-looking.) We have a few poplars, also very tall, between our two houses. The neighbors asked if we wanted ours removed too but I didn’t get the email until after the fact. My trees look perfectly healthy, though certainly very tall. It is unclear where they would fall. The neighbors apparently got the necessary permission and have to replant a certain number of other species with a certain diameter. I spoke to the local arborist who did the work, asking about the danger. He said they are short-lived and WILL come down in our lifetime so although he did not encourage or discourage us to remove ours, he obviously leaned toward removal.
We’re concerned now that IF we have any problem with these poplars in future, we were sufficiently warned and would be liable. Or at best, that we knew of the dangers. Should we take them down? Do Mainers believe this “as gospel”? Does anyone keep poplars in their yard? We are from Ohio and had small aspens and love them… “quaking” in slight breeze. (Plus, in my mind, everything is “habitat”. I don’t remove any lovely viable tree unnecessarily.)

A. Populous tremuloides, Quaking Aspen or Poplar (common names) is generally considered a short lived tree though the US Forest Service link in this sentence states it can live between 150-200 years, certainly beyond the average person’s life span. It is considered to have a softer wood than most New England hardwood trees and therefore, can be blown down easier than other hardwoods when it grows in an open exposed area. 

If it appears healthy and is not threatening a building structure, and as you say, you enjoy the “quaking leaves” as I certainly do, I would not cut it down. They also colonize – or send up new shoots from the root system, which is probably why there are several in the area where you and your neighbor live. In fact, it is believed to be the world’s oldest and biggest living organism due to its colonizing behavior. Certainly something to behold and admire. I have some on my property and the only problem I have with it is it keeps coming up in the middle of my lilacs and other woody perennial shrubs. I just smile and prune it back to the ground when it distracts from my landscape. Only if it becomes weakened and is threatening a building or an outdoor gathering space would I take it down as a safety precaution.

Golden rodQ. I was pulling huge volumes of crabgrass in a challenged part of our meadow-to-be and came across clumps of this plant. Might it be a form of goldenrod? It’s about to bloom into yellow flowers. If it is native, I’d prefer to keep it.

A. Yes, it does look like one of Maine’s native goldenrods. They are great for nurturing pollinators in the late summer and fall, so you are smart to keep them! Here is a website that describes our native goldenrods.

Q. I live in York, on the South Berwick end. I’m on a hill and find the first frost usually doesn’t hit me. What zone would you say I’m in? First and last frost dates, please?

A. It is very hard to predict when the first frost is going to occur in a certain area. It is important to watch the evening weather report to get the prediction for the next morning. The coldest part of the night is usually just before dawn.

The National Weather Service does keep track of maximum and minimum temperatures including the first frost of fall in Maine.

Here is a link to a National Weather Service page that has a number of national maps for median, earliest, and latest first frosts of 32 degrees and 28 degrees. You can enlarge the page to get a good look at southern Maine.

  • The Median date for 32 degrees southern Maine is Sept. 21 to 30
  • The Earliest date for 32 degrees in southern Maine is August 21 to 31
  • The Latest date for 32 degrees in southern Maine is October 21 to 31

What will it be for 2020? No one really knows for sure.

Sorry for the long winded response to this very important question.

We do have a factsheet to help gardeners extend the garden season on both ends of summer. You are already a little ahead of your neighbors by the location of your garden at a site that gets frost at a later date than neighbors.

CrabgrassQ. Is this just a type of crabgrass? It is popping up and spreading aggressively in bare soil areas where we removed old railroad ties and left bare unattended compacted soil (a mistake). I’ve been pulling it now that I noticed it, but it is outpacing me. The spreading ground-level arms and the shoots off those arms are impressingly tough and vigorous. Some of the arms are 2 feet in length or height. I’m curious, what is it and where might it have come from?

A. It does look like crabgrass to me. Chances are the seed was there in the ground waiting for bare soil to germinate and grow. The soil in that area must be very fertile so the grass could grow very fast. Crabgrass is an annual, so try to keep it from going to seed by either hand pulling or tilling in.

If this is going to be a lawn area, plant desirable grass seed now. Here is our factsheets on establishing a new lawn and maintaining a lawn.

Q. I have a beautiful bunch of blackberries that are starting to ripen. But I’ve noticed that on some of the new growth canes near the very top in the really soft young leaves, they are starting to curl up and inside each place I see a tiny green worm. This activity is more or less ruining the top growth of the new canes. Any ideas?

A. There are a number of insects that attack brambles, including the common raspberry cane borer. Can you please send a few photos of the pest and the plant and we’ll go from there?

Q. My garlic leaves started molding early in the curing process. They’ve only been out of the ground for a week and I have spread them out more since noticing. It is white mold, mostly on leaves that weren’t spread out properly. Is it prudent to prune off the leaves? If I leave say 10 inches of the stem is that enough for hardneck garlic to finish curing? Will cutting the stems introduce mold into the stem if I cut the stem now? Will the molds just die away with proper ventilation since it’s early in the curing? Have I just lost my entire crop of garlic?

A. There are several diseases that could be in your garlic. You can cut off the tops and cure without tops at any time. Here is our Growing Hardneck Garlic in the Home Garden.

I would suggest that you send a sample to Orono to be sure there isn’t one of the more harmful diseases in your garlic. Here is the site, Plant Disease Diagnostic Testing for information on submitting a sample to our plant disease lab.

Q. What is going on with my broccoli plants this year? Good soil, well nourished, even irrigation, planted from seed BUT reaching for the sky with no heads developing at all! Most often covered with very light weight rowcover to discourage cabbage moths.

A. I’m not sure if it was the extreme hot weather, or a new invasive pest that was discovered in Maine last year, Swede Midge. Please consider sending in a sample to our insect diagnostic lab for confirmation.

The lightweight row cover could have contributed to the heat build up and failed heads, but it is usually a very good method to reduce the cabbage moths. 

Q. I’m establishing a new lawn, and have successfully eliminated crabgrass both through using pre emergent and post emergent herbicides. I’ve seeded quite a bit with Scotts Sun and Shade, which is mostly ryegrasses, bluegrass, and fescues. Also, fertilized and watered and the lawn is looking good. Only problem is I have lots of what I think is St. Augustine grass riddled through the lawn. I’d like to get rid of it. Any suggestions, other than just digging it out?

A. St. Augustine grass does not grow (or at least overwinter) this far north. It’s found in much warmer climates;  on the East Coast, Virginia is considered its northernmost range.   So, we need to get a positive ID before giving a recommendation. If you can send high-resolution photographs, that would be very helpful. Best would be:  the plant as it is in the landscape;  dig up a plant or two and show the whole plant (or a segment);  then close-ups of the collar region–where the leaf meets the stem–from all angles;  if the plant is in bloom or has a seedhead, photos of that as well. Grasses can be very difficult to identify, so good, close-up photos are essential.  

If it is indeed a perennial grass, control can be difficult, since your lawn is already a stand of perennial grass. Definitely digging it out is one way to go. Herbicide options are likely to be limited or non-existent in this situation, but we can see once we get a positive ID.  Some other resources that might help are the UMaine bulletins, Establishing a Home Lawn in MaineMaintaining a Home Lawn in Maine, and Steps to a Low-Input, Healthy Lawn.  

Slime moldQ. I have a cream-colored frothy something growing on some of my mulch in my flower beds. Some is even growing up a Daylily. Is it a problem? If so, how do I deal with it?

A. This is a slime mold, which is common on bark mulch at this time of year.

Slime molds are harmless to most plants, pets, and for the most part humans. These organisms are saprophytic, meaning they derive nourishment from decaying organic materials, and will not attack living plants even if they are found on plants. If cosmetically slime molds are an issue, you can collect the plasmodium and throw it away. No pesticide is recommended for managing this organism. There’s more detail in this fact sheet, Slime Molds.

Larvae frassQ. It seems either our trees or critters in the trees are emitting these dark brown balls, about the size of a course ground salt, that are very hard and dense. When they get wet they turn into a mush of what looks like algae. Then when they dry up again it leaves this unsightly tan colored smear. What is it and is there anything we can do about it?

A. Thank you for submitting the photos and identifying the tree as an oak, that was very helpful. I suspected upon looking at your photos that the black substance in question falling from the oak trees was insect larvae frass (larvae poop) and that the mush you described later staining your lawn furniture was from the subsequent decomposition. I did reach out to the Maine Forest Service Insect and Disease Lab and they confirmed my thoughts. 

The Maine Forest Service confirmed the photos as insect frass but were not able to identify the species of caterpillar in question. The good news is that Brown Tail Moths are no longer feeding and you have not had an allergic reaction. I know this is a nuisance and not something you want on your lawn furniture. However, I do want to point out that oaks are what is known as a Keystone Species, upon which hundreds of caterpillars (which later metamorphosize into butterflies and moths) depend on for food. Songbirds feed thousands of these larvae to their young everyday. Larvae are a much more important food source for songbirds than bird feeders are and their survival depends on them feeding on native species such as oaks. 

I know that this information doesn’t help you do anything about the frass staining your lawn furniture. However, if you could cover the lawn furniture with a tarp or sheet when you are not using it this would prevent the staining. If you would like to get the species of larvae identified, if you are able and can safely do so you could beat some of the branches (good shake with a stick or long handled garden tool is lower branches are accessible) over a tarp spread out below to see what caterpillars fall out of the tree, you could collect the specimens and send them to our UMaine Extension Diagnostic and Research Lab for identification we could identify the species for you. Be sure to wear long sleeves and a hat to protect yourself from a potential allergic reaction and then launder your clothing immediately afterwards. However, even upon identification of the larval species, there is little you could do to stop the larval feeding in a large mature oak as the branches are so high and more complex and expensive treatments are not practical or recommended due to the important role the insects play in supporting our ecosystem, and specifically endangered songbirds. 

This is probably not the answer you wanted to hear but protecting your furniture with a covering is the best overall course of action.

Q. To over winters in Maine, how large should a compost pile be for red worms?

A. 3 feet high by 3 feet wide would be ideal to give them the insulation they need to survive the winter.

Q. I bought a half moon Japanese maple and planted it on a slope. It died a couple of years ago. I looked at the dead tree and noticed a Japanese maple shoot! What should I do? Suckers do not make strong trees I’ve been told, but I would love for this tree to survive. I would plant it somewhere else. How could this happen?

A. The new sprout could be a sucker from its root stock, or if above the graft, the Half Moon that you purchased. That would be exciting, since it’s a very beautiful variety.

Unfortunately, now is not the time to transplant. It’s too hot and dry, and JMs tend to do best when planted in early spring. Is there any way you could just pamper it in place and move it when it’s still dormant in early spring?

To keep it healthy for now:

  • Weed around the base and check to see if you can see the root flare. If not, gently try to expose it a bit.
  • Mulch with 2″ of shredded bark in a 2′ – 3′ diameter ring. (Keep mulch away from the trunk.)
  • Water deeply once a week. Japanese maples are very sensitive to overwatering and being too dry.
  • Don’t fertilize. You want the tree to slowly go dormant before winter.
  • Decide where you’re going to put it next spring. A place that’s in dappled sun out of high winds is best.
  • You can prepare the soil now and do a soil test. (They like a slightly acidic soil pH of 5.5 – 6.5).

How to plant next Spring:

  • Dig a wide hole that’s not too deep.
  • Use no more than 20% bagged compost by volume mixed well into the native soil.
  • Always remove the burlap and cage, and gently tease the roots so they spread out into the hole. (Roots go laterally, rarely straight down.)
  • Do not use fertilizer in the planting hole. They are salts and can damage fine roots. (If planted well it won’t need fertilizer.)
  • Water deeply if needed once or twice a week, but not each day. The roots are fine and can’t handle saturated soil.
  • Use a ring of bark mulch to keep roots moist and cool, but avoid touching the bark. The bark is thin and can split and rot.

More about Japanese Maples from UNH and Morton Arboretum.


QuackgrassQ. Is this witchgrass? It is spreading vigorously in a “meadow to be” area. At first I thought it might be crabgrass (on steroids!) but it may be another grass. In any case, it looks and acts like an invasive.

A. Thanks for the photo. It looks to me like there are claws wrapping around the stem. That would confirm that it is quackgrass. Some people also refer to it as witchgrass, but there is another species with that common name, just to confuse things.

GoldenrodQ. This plant has been growing in several areas and spreading in flower beds and shrubs. Many others out in the meadow, or just about anywhere, Most are now are about three feet tall, or taller. I’ve been waiting to see what they will turn into but they don’t seem to be preparing any buds. They can be easily pulled out. Can you help identify it, and is it native?

A. This plant looks like one of the plants in the genus Solidago, or goldenrod. There are at least 25 species in New England. This one looks like Solidago rugosa but there are others with serrated leaves. (It looks like there’s a narrower species in the background, too.)

This plant is considered by many a weed, and is often blamed for hay fever. (It’s actually ragweed that triggers an allergic reaction in people.) Goldenrod is one of the most important plants for pollinators and other wildlife, partly because it’s a late bloomer and sustains them into the winter. Here’s a nice article from the National Wildlife Society about goldenrod.

Schefflera PlantQ. I recently (6-8 months) propagated a leaf from a friends Schefflera plant and lately the leaves have started curling under. I see no signs of pests of any kind. What could be causing this?

A. Leaf curl is probably caused by an environmental problem. It’s a very small plant, so the roots are probably very delicate and sensitive to water (too much or too little), heat, and the salts in fertilizers. (Best to hold off on fertilizing new plants with tender new roots).

It may be best to put it out of direct light while it tries to recover from stress and become established in the pot. They like indirect light and when older, brighter indirect light. To encourage roots to head down into the lower part of the pot, water from the base so the soil and roots wick it up. Allow the soil to become relatively dry between watering as this plant does not tolerate wet roots. (Clay pots dry more quickly.)

If the plant perks up, you might allow it to have a quiet dormant period this winter. Most houseplants benefit from this. Then fertilize gently in late February to “wake them up” again.

Here’s a fact sheet from Clemson on growing Schefflera.

Q. I have two Pawpaws growing about 10 feet apart. They are both on a drip line and get about the same water. The moisture level in the soil is about the same. Photo NC-1 appears in good shape, growing vigorously, while photo PA-Golden has yellowing leaves and doesn’t have the same vigorous growth. What do you think is going on? I had the soil tested this year, and I didn’t see any major discrepancies.


A. I have never grown Pawpaw but find it an interesting fruit, worthy of trying in southern Maine where it is marginally hardy. I see you live in York, so hardiness should not be a problem for you assuming the varieties are suitable for zone 5. From your descriptions and photos it appears you have two different varieties, NC-1 and PA Golden. Sometimes one variety may be better adapted to a location or site than another. The yellowing does not appear to be nitrogen deficiency as that would manifest with the lower leaves yellowing, rather it appears to be an environmental factor and not a disease or insect issue. From the photos it appears possible that the mulch is a bit thick and, with you using drip irrigation, could the soil be staying too wet?

When were these planted? Is it possible that NC1 came through the winter in better shape and may be more hardy for our climate? In general they do look pretty good. I might remove some of the thickness of the mulch so that is only 2-3 inches deep and move it away from the base of the trunk a few inches. Water deeply 1-2 times per week and let them dry out in between. Let us know how they continue to develop and we could do some further diagnosis if it does not improve.

Q. My cucumber plants developed bacterial wilt. I used a spray to try and control/slow down the wilt. I know it can’t be a cure but I’m wondering if the cucumbers are still safe to eat? I removed the leaves and fruit that were affected but I understand the infection is systemic.

A. You are correct in that once affected cucumber bacterial wilt can not be cured, but the cucumbers are safe to eat. This Fact Sheet covers the disease cycle and how to prevent it next year. Also, this UMaine Extension Fact Sheet on the Striped Cucumber Beetle covers how to control what is often the pest that transmits the virus, which is an important preventative step for next year.

Container tomatoQ. I have black spots on my container tomatoes (see photo). Any suggestions?

A. A number of us have looked at your photo, and the consensus is that it’s probably not a disease. The larger dark spot could be blossom-end rot, which is very common in container-grown tomatoes. That is the result of insufficient calcium early in fruit development. It often appears when the water supply to the plant is irregular, which regularly happens with container-grown tomatoes. It’s also possible that this larger dark spot is the result of physical damage, such as pecking by birds, and then that damaged spot started to decay. The smaller dark spots could be the result of probing by an insect.  Keep an eye on the plants, and let us know if you see symptoms on additional fruit.

Q. Can you offer any advice on the management of ants in my yard?

A. Maine has many species of ants. See our fact sheet on ants.  Each species has its own life cycle, preferred food source, habitat, etc.

If you would like to send some close-up photos of the ants and also a few images of their presence on the ground, that would be helpful for ID. Once we know the species we can go from there.

Rosa CarolinaQ. I am writing to identify a rose we have recently discovered growing on the edge of the woods on our property. We have never noticed this plant before, but it is quite big. At first I was really excited to see it because it looks like rugosa rose to me, but then I remembered a neighbor mentioning something about an invasive rose on her property. Can you identify the rose in the picture and advise if it is an invasive plant?

A. Our horticulture team concluded that your pink rose is not the invasive multiflora rose, but more likely our native rosa carolina or rosa virginiana. They have very slight differences in stem and leaf anatomy, but both are great pollinator plants and the hips are food for multiple bird species.

One way to ID multiflora during any season is by its shape and aggressive growth habit. Even when young, the branches arch and can even climb upward. Our native roses are relatively short, finely branched, and are not aggressive in the Maine landscape.

Queen Anne's LaceQ. I have either Giant Hogweed or Poison Hemlock in my garden, which has caused an allergic reaction in me. What is the best way to remove it?

A. It appears that the photos you submitted are the common Queen Anne’s Lace, Daucus carota, which is in the same family as Giant Hogweed. Some people experience a “phytophotodermatitis” skin rash. This is common with this Apiaceae family of plants and can be exacerbated in sun and hot weather.

The good news is it is not either Giant Hogweed or Poison Hemlock. I don’t think you need to eradicate the plants but avoid them in hot sunny weather. You certainly could put on a pair of gloves and long sleeve shirts and weed them out and then launder the clothing you are wearing.

Q. I have an area of my yard that has been sectioned off and filled in with a weed barrier and crushed stone. We replaced the weed barrier 2 years ago, but the weeds are continuing to take over the space. We are not wanting to use round up as our children play in this area. We would love to use this space more, but don’t due to the overgrown nature. Looking for suggestions on a natural weed killer. Any help would be appreciated.

A. Unfortunately, there is no “natural” herbicide that would provide the same control as a glyphosate product (like Round Up). Unlike glyphosate, which is a systemic, meaning it is translocated to the roots when applied to actively growing foliage, most “natural” herbicides only work on contact, which means they will kill foliage but have no effect on roots and regrowth, so they are unlikely to provide 100% control with one application. Additionally, because many of them are exempt from EPA testing, there is very little data on the environmental risk or risk to those who apply them (even “natural” products are not risk-free). You should always follow label directions for any product you apply. For more information on natural herbicides, and their limitations: check out this site, Natural Herbicides: Are they effective?  (which includes a list of some products) and this well-written explanation, from Maryland Extension, Vinegar: An Alternative to Glyphosate (PDF)?

Are the weeds a kind that could be controlled with a non-herbicide alternative? Perhaps you could use tarping to smother them and then create a suitable play area by either periodically reapplying wood chip mulch or establishing a small patch of low-input lawn. I’m happy to help ID the weeds if you’d like to send me photos. That might help narrow down suitable control options.

meadowsweetQ. This small shrub is quite prevalent around the house area. Earlier this year, I thought it might turn into a honeysuckle bush of some kind, but now that it is flowering it is clear that it is not. Can you help identify it and is it a native?

A. The plant is a native called meadowsweet, Spirea alba.

It’s a great pollinator plant (PDF). There are lots of cultivars available for the garden, all deer-resistant.

Q. We have a protected plant growing, Pale Jewelweed. Can they be cut down to put in a driveway or should we access a different area that is growing Japanese Knotwood?

A. While there is no legal reason you could not put your driveway where the rare plant, Pale Jewelweed, Impatiens padilla, is currently growing, if you have an alternative suitable location for your driveway that would certainly be preferable and help maintain a species which is classified as rare and of concern.

There is no reason why a driveway can’t be located where the invasive Japanese Knotweed, Fallopia japonica, is located. An excavator preparing the site for paving would be able to remove the majority of plants, roots and rhizomes. Any remnants of roots and rhizomes would try and regrow but they would not be able to penetrate an asphalt driveway. One way we recommend control of this plant without herbicides is to smother it by cutting it back and covering the ground which it occupies with something thick such as carpet remnants which prevent the resprouting. Certainly if a carpet remnant can stop its regrowth then an asphalt driveway also can.

Q. Looks like my Common Ninebark has developed some type of fungus or mold on the leaves of the lower third of the bush. Is it over watering or extreme weather conditions?

A. Since I have no photo, I’m following up with some general information.

Here’s our fact sheet about Selecting, Planting and Caring for Trees and Shrubs in the Maine Landscape.  And information about Ninebark from the Morton Arboretum.

One of the few problems this hardy native sometimes gets is powdery mildew. If you think that’s what you have, here’s a good fact sheet from the University of Minnesota about Powdery Mildew on Trees and Shrubs.  It may be unsightly, but will probably not harm the plant. One of their recommendations is pruning. Here’s more about Pruning Woody Landscape Plants.

If you don’t think your plant has this, please send photos and we’ll go from there.

Eriophyid mitesQ. I have a newly found tree problem. The leaves of my trees are covered with hundreds of raised “projections” which today have unfolded and grown, looking like new alien growths (see photo). I have never had this before. What can I do?

A. The pest appears to be caused by eriophyid mites which feed on the tree’s leaves and cause the strange looking formations called spindle galls. The good news is the damage is purely cosmetic and does not harm the plant which tolerates the feeding and the resulting formation of galls, which the insects live inside of. Alien looking indeed!

Early blightQ. Three years ago, I had a lovely crop of tomatoes. Two years ago, the tomatoes got some sort of blight later in the season and the beautiful, but not-quite-ripe tomatoes rotted on the vine. Last year, they got some sort of early blight or fungus after only a few tomatoes formed, and I got nothing. This year, they again have whatever they had last year. I have raised beds, but the tomatoes have been in different locations every year. Last year, they were in pots on my deck. This year, they are in a new raised bed near the other two raised beds.

I only have four plants, each a different variety. All four plants now have spots on their leaves (see photo) and also have a bunch of green tomatoes growing.

What is the problem? What (if anything) can I do to save my tomatoes this year? Preferably something organic. What can I do next year to prevent this from happening?

A. From the photo you attached it appears to be Early Blight which is a very common disease of tomato and difficult to control.

Prevention is the best means of avoidance, and methods include good garden sanitation by removing all diseased remains of the plant early in the season, using crop rotation and planting resistant varieties. You note that you did use crop rotation but it is still difficult to avoid, especially in a home garden situation where crop rotation might not encompass a large enough area to prevent recurrence of the disease.

Other prevention practices include good air circulation around the plant through proper pruning and trellising or caging of indeterminate varieties, removing the lower leaves of the plant as it grows early in the season up to the first flower cluster, and mulching around the plants once the soil has warmed up to prevent splashing up of the spores from the soil.

Here are links to Early Blight Control and Organic Early Blight Control (PDF) from Michigan State Extension

Take heart in that you are not alone battling this disease as almost all homegrown tomatoes are affected to varying degrees and this season, with the recent humidity, is very conducive to the spread of it.

Q. My tomato plants are turning yellow. I’m not sure what to add to the soil. I built the bed last summer with a layer of bark mulch, a layer of seaweed and a layer of garden soil. Any suggestions?

A. It sounds like your tomato may be missing some important nutrients like nitrogen, perhaps due to the soil mix.

Bark mulch is fine for a top mulch, but when incorporated into soil it can cause problems for plants. Bark, wood chips and shavings can cause “nitrogen lock-up”, where soil organisms actively consume the carbon, using all available nitrogen in the process. Seaweed is also a good mulch, especially for overwintering garlic.

For raised beds, we recommend 75% screened loam (the mineral component of soil) with no more than 25% organic matter (finished compost) mixed together well. This provides most plants with the nutrients and soil structure they need to be healthy. Tomatoes are “heavy feeders”, so they often need some additional fertilizing based on a soil test.

Another cause of yellowing could be too much or not enough water. The plants need about 1.75″ of water a week, probably more in a raised bed since the drainage is usually good. Tomatoes also appreciate being watered from the base since wet leaves can cause diseases. Be sure to allow the soil to dry between watering as roots need oxygen to function.

Since your plant is not doing well, try giving it a gentle boost of fertilizer with nitrogen. Dilute according to instructions, and see how the plant responds.

A soil test can give you a good picture of your soil and what it might need to improve in the coming seasons. Here’s a video about preparing your soil, including how to test your soil. Here’s where you can find the soil test form and instructions.

If you think there’s a different problem with your plant other than fertility, please send a few photos. One close up and one of the entire plant.

Q. I am wondering about my little leaf cucumbers, they have a seemingly very dry stem and is turning gray, white as it turns woody. Wondering if you have any thoughts? The plants seem healthy otherwise and are producing. Mild cucumber beetle pressure. Large snail presence with no noticeable damage. Photos won’t upload for some reason.

A. It’s possible that particular variety has less resistance to a particular disease, which would explain why you aren’t seeing it on all your cucumbers. If you could send those pictures that would be very helpful to narrow down the problem! Hopefully they are easier to attach by email (they may have been too large to send via the website which has a 1 MB limit).

Flowers/sumacQ. Can someone help me identify this plant. I believe is a type of sumac. I would like to use it in market bouquets, but would feel more comfortable doing so if I knew what type of sumac it is. Last year my husband and I waddled a fence out of the stems and had no problems with skin irritation and I use them in my own bouquets at home all the time.

A. The specimen you photographed is our native Staghorn Sumac, Rhus hirta. Contrary to what some people think this plant is not poisonous like Poison Sumac, Toxicodendron vernix, an unrelated species. If you look at your photos and compare the leaf images to these two plants you can clearly see the leaf margins are toothed like in Staghorn Sumac like the photos you sent. Rest easy and use it in your market bouquets.

Q. Why are my zucchini leaves turning yellow/brown and dried out?

A. There are several reasons why Zucchini leaves could be yellowing. When this has occurred in my garden in southern Maine, quite frequently the culprit has been the striped cucumber beetle, which in addition to causing root and plant damage, can also transmit diseases such as bacterial wilt, which does cause yellowing and wilting of the leaves and ultimately can kill the vines or set back your yield significantly.

This University of Minnesota Fact Sheet has some good images of a variety of possible insects and diseases which can cause problems for Zucchini and Squash plants.

You are welcome to please send us a photo which would help us to more specifically diagnose the problem for you and be able to make the appropriate recommendations.

Q. I have broccoli plants in three different locations. All of them have very large green leaves and no heads, just some tiny florets. What is going on?

A. It sounds as though your broccoli plants are doing what is called “buttoning.”  It’s typically a response to stress that occurred early in the plant’s development. It might have been cold weather, dry soils, overly-mature transplants, insufficient nutrients, or other conditions. See, Buttoning in broccoli and cauliflower, from the University of California.

Q. I live in Falmouth. This year I see a lot of chipmunks/tiny squirrels in my garden, that is creating a havoc by digging the raised beds. I have tried putting a chicken fence around the raised beds, and now I have built fence around all my raised beds, and still they are unstoppable. My tomato plants are flowering now, and I am worried about how to save the tomatoes when the fruit is set.

I obviously do NOT want to harm them in any way, but want to repel them and save my plants/fruits. Can you suggest an option for this please?

A. This seems to be a banner year for chipmunk activity as last year was a big acorn year. For control strategies we recommend you contact the USDA Wildlife Services office in Augusta at:

Phone: 207.629.5181

USDA Wildlife Services
79 Leighton Rd., Suite 12
Augusta ME, 04330

Stalk in meadowQ. This odd plant has started showing up in a “meadow to be” area that we are not mowing. It has a long, segmented stalk, some about three feet high for now. I wasn’t able to pull out the root or rhizome, the plant broke off at the base. Could you help me identify this and should I be concerned? See photo.

A. The plant in the photo is common valerian (Valeriana officinalis). It is a non-native species, likely escaped from cultivation, and is listed in Maine as having the potential to be invasive. There is a valerian native to Maine (Valeriana uliginosa) but it has several distinguishing features including fewer leaflets on the leaf blades on the stem.

Q. I started an apple tree from seed and it’s now planted in the front yard about six feet tall. It has a double trunk, and I’ve held off pruning the shorter one off so as to keep maximum leaves exposed in order to support the root stock, but at some point am going to have to reduce it to one main trunk.

When will my tree reach sufficient maturity to cut it back to one trunk?

A. Reshaping your tree is best done while it is small, and your tree is large enough to prune it to one main trunk at its current size. The ideal time to prune fruit trees is late winter into early spring. However, summer pruning can also be performed, although severe pruning may weaken the tree. Therefore, the majority of pruning should be done during the winter or early spring.

As your tree has been started from a seed, it may grow quite large. I would suggest planning for giving it plenty of space to grow, up to 20 feet.

Q. I have never had such a huge problem with moles in my vegetables. They undermine the roots with their tunnels. I stamp down tunnels every day, but I have vegetable, herb and flower gardens and I can’t even make a difference in the vegetable garden. Spinach crop was probably 50% of normal. I have set snap traps in the tunnels and caught two moles, two shrews and one white footed mouse. The damage continues unabated. I would rather exclude or repel than kill, but how? And if I must kill, what’s the most humane way?

A. This page, Living With Wildlife, from the Department of Inland Fisheries and Wildlife has an extensive rundown of mole control measures. For non-lethal control measures, exclusion is the best option but this could be costly depending on the size of your garden. Raised beds can be constructed with wire underneath. While that page lists a number of lethal control measures, this one, Controlling Damage From Moles and Voles, from Alabama Extension also provides good visual references for the various types of traps. Another good resource is the Wildlife Services division of the USDA APHIS, contact info is listed on their website.

Q. I think I have an infestation of leafhoppers. Is there a safe, organic way to control them? I use the salad greens to feed my chickens and am hoping for a method that doesn’t require washing before consumption.

A. The first step would be to confirm that what you have is indeed leafhoppers. They are small, green, wedge-shaped insects that tend to fly up when a plant is shaken or disturbed. Sweep nets can also be used to catch them. Because leafhoppers suck out plant juices, damage will appear as yellowing, curling and stunting of leaves.

Control options:

  • Row covers can be used to protect plants but must be removed at flowering.
  • Keep weeds down, especially perennial weeds, as they can harbor leafhopper eggs.
  • Because there are many natural enemies that help control leafhoppers, be very cautious with any chemical control options so you are not impacting beneficial predators.

From University of Maryland Extension, Potato Leafhopper, Vegetables: “For large numbers, use botanical insecticides such as insecticidal soap, horticultural oil, neem, pyrethrum, or combinations thereof. Spray early in the day when insects are sluggish. Thoroughly wet leaf undersides. Apply repeatedly for large populations.”

Make sure your pesticide is labeled for the pest and crop you plan to spray it on. Follow label instructions including any pre-harvest interval (the time between when you spray and when you can harvest) for yourself and your chickens.

MMountain Ash Sawfly larvaeQ. Our back yard mountain ash has many leaves stripped down to the center vein. Many of the wild phlox have suffered the same fate. The photo shows the damage to one branch, and the caterpillars doing the work. What are our safe alternatives to protect this small tree?

A. The mountain ash has Mountain Ash Sawfly larvae. They are not caterpillars, so some products like Bt will not work on them.

Here’s a good fact sheet about the insect, its life cycle and how you can control it.
Mountain Ash Sawfly from the Maine Forest Service.

One method not mentioned is, if the tree is close to a hose, you can blast them off. This disrupts their feeding and knocks them on the ground where the birds will feast on them.

Q. I believe my young grafted Baldwin has fire blight. What should I do for treatment?

A. Fire blight is a possibility, and Baldwin is particularly susceptible to it. It would be best to confirm the diagnosis with UMaine Extension’s Plant Disease Diagnostic Lab. Photos might be sufficient. Email them to Dr. Alicyn Smart,, and be sure to include your name, phone number, business name, county, host plant, problem, date when symptoms were noted and good, in-focus images.

If it is fire blight, management recommendations are described in this Fire blight outbreaks article from UNH. It includes information about how to prune out infected branches at this time of year and how to sterilize tools. Be aware that the fungicide mentioned for consideration (Cueva) is only labeled for commercial use, not home garden use.

Q. Which compost mix would you recommend for shrubs and perennials in very sandy loam that hasn’t ever had any amendments? Would straight composted cow/horse manure be best or half manure half green waste?

A. Building your sandy soil’s organic matter by adding compost is a very good idea to help the soil hold water and retain nutrients. Compost from either source (horse or composted greens) would be equally fine. The only risk, if you are composting your own horse manure ((vs. commercially purchased compost) is that some weed seeds will likely survive the compost process and you could introduce some weeds you will later have to battle. With commercial compost or compost that is well heated and turned during the process would kill off any weed seeds.

Here is a link to our bulletin on Home Composting, and for more resources, a link to our Master Gardener Manual chapter on Composting.

VincaQ. I have been establishing native plants on our property for a few years now. In the past, I have planted invasive Vinca which is spreading to the woods. Very time consuming to control! I recently found some Pyrola Minor growing among the Vinca. I’m thinking the best course of action is to try to keep the Vinca thin in that area. I’m afraid to pull it all out as the Pyrola seems shallow rooted. Suggestions? I live in Durham and was surprised to see this plant. I thought it was only found further north.

A. I have also experienced Vinca, which I planted in my garden many years ago, escaping into wild non-landscaped areas. It is not listed on the Maine Invasive Plants web page, however, as you have noticed it does have invasive tendencies and is of concern. Your question about how to thin it with another plant you are trying to protect growing near it is very tricky. You are correct, in that it would be hard to pull without disturbing the plants within its vicinity. Vinca spreads through trailing vines/stems which root as they touch the ground. You could try to very carefully lift up and cut off the vines to prevent them from rooting and spreading further.

This would only be a short term solution as the Vinca will resprout new trailing vines and you would have to continue this process. Using any herbicide would be extremely difficult without also taking out the plants growing near it so I would not recommend that. I am afraid I don’t have a very good answer for you besides keeping it from trailing in order to slow down its spread, but it does want to naturalize and will be persistent.

Browning leavesQ. I have bush green beans and pole beans in my garden. The leaves on both types are curling and yellowing. Do you know what is causing that and how to correct it? Attached is a photo of a pole bean plant taken shortly after three days of rain totaling about 2.5″. The problem started prior to the rainfall event. I have planted similar type beans in my garden before and they thrived, looking much better than these.

A. From your picture, it looks like “hopperburn,” the term for damage caused by leafhoppers. Leafhoppers are flighty so if you brush past the plant, you may notice small insects flying away. From our fact sheet on sucking insects: “Leafhoppers are small, green, wedge-shaped insects that attack many garden, forage and fruit crops. They suck out plant juices causing yellowing, leaf-curling and stunting. They also transmit several disease organisms, especially associated with yellows. Use pyrethrins or carbaryl (Sevin) as a control.” Make sure any pesticides are labeled for your specific crop and read and follow label directions. Row cover can be used to protect young plants until flowering, although this may be less effective if the insects are already present.

Q. I am doing raised beds for the first time this summer. I have Eureka and Marketplace cucumbers and am wondering if I need to stake or trellis them?

A. Although the plants can be allowed to grow on the ground (raised bed or not), trellising will not only save space but will help provide longer and straighter cucumbers. Growing upright will make it easier to harvest and also keep the cucumbers cleaner.

I did see reference to the Eureka variety with recommendations to trellis. I didn’t find Marketplace but did find a couple of Marketmore varieties; they also recommend trellising. Unless you grow a bush variety of cucumber, trellising is a good idea.

To learn more, visit the Cornell University website about growing cucumbers, which you might find helpful.

Q. Unfortunately, it seems our hemlocks have been infested with woolly Adelgid this year. We pride ourselves on not using chemical fertilizers and pesticides in the yard. I’ve read that the most effective treatment is to use a systemic insecticide and am very hesitant to do so. It seems another alternative is to use a horticultural oil or insecticidal soap, although I’m not confident we can get it applied high enough up the tree with a pump sprayer. Do you have any experience with any of these products? If we give the horticultural oil or insecticidal soap a try and it doesn’t work have we lost valuable time with the hemlocks? Are the horticultural oil and insecticidal soap used in conjunction? Any advice you have is greatly appreciated.

A. I’m sorry your trees are infested. The Maine Forest Service is tracking HWA in Maine and would like you to report it to them.

For more information about the insect and how to control it, visit this HWA fact sheet (PDF).

Crown vetchQ. I have about an acre and a half meadow behind my house on MDI with a stream at the bottom. Sadly it has become invaded by crown vetch. I didn’t plant it! It may have been here when we bought the place and I didn’t notice it right away but it is taking over now. I’ve read the best way to control is to just keep mowing it. Sadly, that mows the native grasses and wildflowers, too. Is there another solution? If it has to be mowed, when and how often? Do you think it would work to just mow the upper parts where it is? It has not spread to the lower section, which has pretty dense grasses.

A. I recommend mowing in this situation. While it’s going to impact the success of some of the wildflower species you’re aiming to keep and wildlife habitat this year, I think it’s an important short-term compromise to make in order to have the best long-term success. Use a grass catcher to try to keep the seeds from dropping and reseeding itself. A couple of years of mowing the vetch when it’s in flower should help get it under control. Also, nitrogen fertilizer would encourage the grass to start out-competing the vetch. A soil test to determine other nutrient needs for the grass is good practice.

Q. Is it safe to eat strawberries that have been irrigated with stagnant water?

A. Our small fruit specialist says, “If they were irrigated via trickle or drip irrigation, there should be no problem. If they were overhead irrigated and more than two days have passed, there should be no problem. If they were overhead irrigated and picked shortly after, they could be rinsed and allowed to dry, and there should be no problem. The farmer should be getting the water tested for problems if they are going to use surface water, overhead, near harvest.”

Q. We have been offered a couple of Selaginella lepidophylla (resurrection plant or false rose of Jericho). We are wondering if we plant the two of them, will they become an “invasive species” that can’t be/would be difficult to control?

A. It’s always a good idea to confirm that an exotic plant won’t become invasive before planting it. The state of Maine has a comprehensive list of invasive and potentially invasive plants that can be a helpful guide for you. It’s very unlikely that Selaginella lepidophylla would become invasive here in Maine for a few reasons. It doesn’t appear to be hardy enough to withstand our cold winters and therefore should be treated as an annual. Also, it is typically found in a very niche habitat of the desert, which is very different from the climate we have here in Maine.

Q. We live in South Portland and there is a drought at the moment. How often should we water our vegetable garden?

A. Ideally, 1.25 to 1.5 inches of rain per week is enough for most gardens. A rain gauge can help you decide when to water.

It’s good to get water down to 5-6 inches of soil depth, but there are a lot of factors at play: your soil type (sand or clay), how much organic matter your soil has in it, what growth stage your plants are in, whether you have raised beds, whether your garden is mulched, how much sun and wind there is, etc.

When watering, it’s better to water deeply but less often; this encourages plant roots to move further down into the soil. Since roots need oxygen, never keep your soil saturated.

Another important tip is to water at the base of the plant (rather than on the leaves) to prevent disease. This is especially important for tomatoes.

How to Water your Garden is a new video we’ve just produced that will give you more info and strategies for dealing with this drought.

Q. I compost my tomato patch (6×10) every fall with two wheelbarrows of horse manure. I bury deep and space my plants 20 inches apart. Every year my plants grow “leggy” (tall and narrow stems), with frail vines, unable to support a good yield, despite adequate water, weeding, and TLC. Please advise.

A. The soil is likely the key factor, but it might also be due to limited light. Tomatoes and other fruiting crops need at least 8 hours of full sunlight for optimal growth and production. Plants growing in insufficient light will develop just as you described: thin, leggy stems, and very little fruit.

Aged animal manures are a common source of organic matter in gardens. While organic matter plays an important role in improving soil structure and the capacity for the soil to serve as a “bank” for nutrients, it is not a potent and immediate source of nutrients compared to traditional garden fertilizers. Annually adding aged manure or compost to mineral soil is a good practice, but it’s important to apply in moderation. Six cubic feet per 1,000 square feet (the equivalent of six 1-cubic-foot bags over a 20′ x 50′ area) applied in the fall is a good target application rate. Applying fully composted manure at the same rate in the spring is also a good practice. It’s possible to add too much organic matter to the soil. Overapplication can actually decrease production because the biological activity can deplete the soil oxygen levels.

To regroup, I would start by having your soil tested (midseason is still a good time to soil test) to get important information about organic matter content, nutrient levels and pH as well as whether you have lead in the soil. Request a soil test kit here. Follow the recommendations on the soil test results to make targeted adjustments to create optimal growing conditions.

Also, it’s best to not grow tomatoes in the same location year after year. Disease and pest pressure can build when any crop is repeatedly planted in the same site. In landscapes where you don’t have an alternative site for crop rotation, consider alternating what you plan to buy at the farmers market and what you plan to grow. Here’s more information from Penn State Extension, on why it’s important to rotate crops based on plant families, Plant Rotation in the Garden Based on Plant Families.

Q. I just bought an astilbe and a brunnera to plant. Now I’m told it’s not the best time to plant them. Is that so? I may have to plant them anyway within the next couple weeks and I have never planted a perennial before. I plan to mix Bumper Crop with the soil. What do I need to remember in terms of “how-to”?

A. It will be best to plant your brunnera and astilbe rather than leaving them in the pot. Here are some helpful hints for planting:

  • Dig a hole that’s at least twice as wide (but not deeper) than the plant’s roots.
  • If it’s a new garden, think about testing your soil so you know what the pH and nutrients are like. (You can plant now and test later.)
  • Moisten the hole, since the surrounding soil is probably very dry right now. Let it drain out.
  • Amend the soil with no more than 20% bagged compost (like your bag of Bumper Crop) and mix well into the native soil. (Do not add fertilizer, which can damage the roots.)
  • Tease the roots out if they’re bound or circling in the pot. If they’re terribly pot bound, you can cut vertical slits to fluff them out.
  • Gently place the roots horizontally into the hole, backfilling as you go.
  • Carefully press the soil around the plant and create a small ring to dam and hold water.
  • Water deeply. During dry spells, perhaps every three days. (NOT DAILY.) The plant needs a chance to partially dry between watering. (Roots need oxygen.)
  • 2″ of shredded bark mulch can help the soil hold moisture and prevent the roots from getting too hot. Don’t smother the stem or crown of the plant.
  • If planted well, you won’t need to add fertilizer. (In the first year, you want to encourage root growth, not top growth.) If you choose to fertilize, dilute well and don’t add any after mid-summer so the plants can go dormant before winter.
  • After Thanksgiving, protect the plants for the first winter with a few balsam fir boughs. Remove them after daffodils emerge.

The Cornell Growing Guides have great info about most perennials and annuals.

Brunnera is a spring-flowering plant and likes shade and moist organic soil. Like most spring ephemerals, it naturally goes dormant around now, so don’t be worried when it starts to turn brown. (That’s why people plant them behind summer flowering plants.)

Astilbe comes in two groups with many cultivars.

If you’re interested in growing fruits, vegetables, and trees and shrubs for the Maine Landscape, bookmark our Garden & Yard website.

Q. Chipmunks are being pests in my garden, any suggestions? Other than hardware cloth underground.

A. Their numbers are high this season, and people are home noticing them more. Unfortunately, there’s no one silver bullet for keeping them from harming your garden. There are some good strategies for reducing their number in this fact sheet from the University of New Hampshire, Chipmunks in the Garden.

Q. Can I grow fruit and vegetables in the same garden?

A. Yes, you can grow all sorts of things in the same garden. Vegetables and fruits (especially small fruits like high bush blueberry, strawberry, etc.), vegetables and flowers, vegetables, and perennial vegetables (like asparagus, rhubarb, etc.). Much depends on the size of your garden and how you lay it out to facilitate the soil needs for the different plants, and the ability to rotate some crops around in successive years. Keep in mind that most fruits and vegetables need 6-8 hours of full sun. Your garden should be where you can visit it each day (close to your home) and easy to tend and water.

We have a series of Victory Garden videos for beginner gardeners. So far there are 6, starting with Vegetable Gardening: Where to Begin. The second one is about Planning your Garden.

Spots on Iris leavesQ. I am looking for a solution to a leaf spot problem on my bearded irises. The foliage starts out green and beautiful in the spring, but gradually develops yellow and brown spots, so that by the fall, almost all the leaves are heavily spotted or brown. I am hoping to find a less toxic option than the Ortho product (Garden Disease Control).

A. I ran this by our plant disease diagnostician and she’d like to see a sample. Please follow the directions on this website.

Q. I am considering a peach tree for my garden/yard in Durham. I have mature pear trees and several 3-year-old apple trees in the vicinity of the planned location for peach. Do I need more than one tree? Can you recommend a variety? I am interested in flavor of course, but hardiness, disease resistance, and longevity trump flavor.

A. Growing in Durham will be relatively easy compared to more northern parts of Maine, where flower buds might get late spring frosts.

Most peach varieties are self-fruitful and do not require another variety for cross-pollination. The exceptions to this are JH Hale, Indian, and Indian Blood. Self-fruitful trees can be expected to produce abundantly when planted alone.

I think most would agree that Redhaven is the best tasting hardy peach. The pit separates from the flesh when ripe, so it’s much easier to eat and process than other varieties. Its flower display is not as fancy as others, but the fruit is very pretty when ripe.

Bare-root trees should be ordered in January or February to avoid missing the deadline (and supply).

Here’s more information about varieties, planting, pruning and care:

Q. My annuals (cleome, cosmos, morning glory, zinnias, sunflowers) are making very little growth and look stunted. I feel that it may be due to an over-application of bark mulch over a number of years. Or could they be suffering from high acid content of soil? Or the drought conditions, though I water thoroughly on a regular basis? One or all of above? How does one change the pH to make soil of established annuals more alkaline? My potted zinnias are hardly growing, although looking healthy. I have used Espoma Flower-tone 3-4-5 once on all of the deck pots and in the ground. Using Neptune’s fish emulsion when watering deck plants.

I have a Sungold tomato in the ground where one thrived last summer. I now remember that perhaps one does not plant tomato in the same spot? It is doing fairly well considering the growing conditions here on the coast here in Boothbay Harbor.

A. It’s hard to know for sure what the issue might be with your annuals; it could be a variety of factors. I wouldn’t worry just yet, it can take some time for your annuals to become established. Bark mulch doesn’t need to be applied every year, in fact, every other year or even less frequent (depending on the quantity) should work fine. I don’t think this alone would have caused stunted growth on your plants. When did you plant your annuals outside? Were they directly sown or planted as seedlings? It sounds like you are watering them well, which is important for establishment. Keep in mind that it is important to water them deeply, wetting the top 5-6” of the soil. We just launched this How to Water Your Garden video as part of our Victory Garden Series that can help guide your watering practices.

I’d recommend that you have a soil test completed for your garden; you never want to amend the pH of your soil without knowing what your current pH level is in your soil. The standard soil test will also give you a good read on what the current macro and micronutrients are in your soil. You’ll receive specific instructions on how to amend your soil to achieve optimum nutrient and pH levels for growing your annuals. You can request a soil test kit to be mailed directly to your house by completing this online form.

You also want to be very careful not to over-fertilize your plants because that can result in a high concentration of salt which can damage the roots of your plants if there are excessive applications, especially in containers. Typically, gardeners can apply a general-purpose fertilizer just before planting, then again as a side dressing 4-6 weeks later.

It’s always a good idea to rotate your crops especially plants that belong to the Solanaceae family, such as tomatoes. It’s probably fine if you planted your tomato in the same spot as last year, just try to rotate it to a new location the following year.


Q. My question doesn’t concern my garden, but I am trying to identify a bush growing wild under the pine trees.

A. Thank you for the great photo! It looks like you have our native Honeysuckle, Lonicera canadensis.

Q. I have a Rose of Sharon in need of pruning. Can you tell me the best time to prune? I just read two seemingly informed articles with entirely contradictory advice, one saying prune in spring or right after the flowers drop, but not in late fall or winter, and the other saying the best time is in late fall or winter.

A. Pruning out dead or damaged branches can be done at any time. If you are pruning it for shape or size and are thinking about how it will flower, then it should be in late Winter or early Spring. For more information, see The Pruning Calendar.

Most shrubs that flower after the end of June produce their flower buds early in the current season, on new wood. These include buddleia, clematis, clethra, rose of Sharon, hydrangea, potentilla, and rose. These shrubs should be pruned in winter or early spring, just before the season’s growth begins.

Here is a wide range of information about growing this beautiful shrub.

Apple Cedar RustQ. This question is about the flowering crab in my front yard. After beautifully flowering in the spring, its leaves have started turning yellow and drop prematurely. What is causing this and what can I do to save this beautiful tree? It’s been there since Dad planted it years ago and I can’t bear to see it looking so bad. I am located in southern Maine.

A. Our Plant Pathologist got back to me in regards to your photos. She has confirmed that you have Apple Cedar Rust. She also said you are probably not seeing any sporulation because it’s too dry, but it will eventually occur.

The other host for Apple Cedar Rust is a plant from the Cupressaceae family (red cedar and juniper). If you are able to tolerate the leaf spots, they don’t tend to cause significant damage to crabapple trees. You can also identify and cut down any red cedar and juniper plants within a few hundred yards of your crabapple if that’s reasonable to do so. Another simple measure you can take is to inspect any juniper and red cedar trees in the winter for galls and remove them before they turn orange and become gelatinous.

Here is more information about Cedar Apple Rust from the University of Minnesota Extension.

lupinesQ. Something is eating my lupine seeds. In one of my three beds, all the lower of the lupine flower stalk is being stripped. Chipmunks, birds, or something else?

A. Is it possible that they have aphids? It’s not quite clear in your photos, but it seems possible and that the leaves still visible are suffering. Lupines are healthiest in full sun, cool temperatures, and well-drained soils. Recent higher temps may contribute to the problem but aphids are a very common pest on lupines.

If you are seeing aphids, a strong jet of water should wash them off the plant, but you may need to repeat that if they return. Here is information about aphids from the University of Maryland Extension.

Q. I gave my clematis a bad haircut at the start of the season, accidentally cutting off live stems. Similarly, last summer, my baptisia got huge and bent over after a hard rain and the advice from you guys was to cut it back.

This year, both plants have come back, but not nearly as robust and full as before. My clematis is about 1/2 of what it was at this time last year, and the baptisia is also quite small, about 1/3 of the size that it was. Both have very few flowers.

Is this to be expected when you generously cut back these two perennials? Can I expect that, over the next few years, they can and will grow back to their big bushy state, or will they forever be sort of small? Is there anything I can do to encourage growth?

A. Clematis: Once established, clematis is long-lived if kept watered during drought, and top dressed in the spring with some compost. Mulch or an overstory of shallow-rooted herbaceous plants (columbine, rose campion, etc.) can keep their roots cool while the flowering vine is in full sun. Most important, clematis come in three types, each pruned differently to keep them healthy and blooming: A, B & C (or 1, 2 & 3).

  • A: Earliest clematis to bloom. Flowers on last season’s wood. Prune minimally (just dead stems). If more is needed, wait until the plant finishes flowering. New growth will then have enough time to grow flower buds for next year. Examples in this group: Clematis alpina, C. macropetala, and their cultivars.
  • B: Flowers on current and last year’s wood. Stems from last season’s wood produce heavily in late spring, followed by a lighter bloom in late summer on new wood. In early spring, only prune dead stems. After the spring flowers fade, the stems that contained those flowers can be shortened. This group is the most difficult to prune, because the vines bloom on old and new wood.  Adjust timing of pruning/cleanup after observing the flowering during the course of a growing season. Examples: Clematis florida and its cultivars, C. ‘Nelly Moser’, C. ‘Niobe’, C. ‘The President’.
  • C: Flowers on new (current year’s) wood, and the simplest of the three pruning types. Bloom in late summer or early fall. Early spring: cut back all stems to buds that are within 12 to 18 inches of the ground. Then let the plant go to town. Examples: Clematis terniflora (sweet autumn clematis), C. ‘Gipsy Queen’, C. ‘Jackmanii’, C. ‘Ville de Lyon’.

If an established clematis is pruned hard or at the wrong time, it will survive. The plant will just flower less, or at a different time than usual. If you’re unsure of the species/cultivar you have, observe its flowering over a full season. After that, you should be able to assign a pruning group and adjust pruning/fall clean-up accordingly. You can sometimes ID the cultivars from catalogs, too.

Baptisia: This is a much more straight-forward plant than clematis! This shrub-like herbaceous perennial can last for years and thrives on neglect since it has very deep roots and makes its own nitrogen. Some people will set up a peony ring to prevent damage during hard rains. (It’s hard to prop up after the fact.) My guess is that it was weakened because it lost some photosynthetic time last season when it was cut back. To nurture it this season, give it deep watering once a week during dry periods, top dress with some compost, keep weeds at bay, and take out any dead material from the center. Avoid fertilizing after mid-summer so it can slowly go dormant before winter. Hopefully, it will catch up and produce flowers next season.

Q. My new blueberry bushes got hit by frost. Will they survive?

A. If your blueberry plants were planted with good, well-drained soil (with the correct pH and fertility), mulched, and given 2″ of water per week, the plants themselves should be okay and continue to grow.

If the flowers were frosted, the fruit may be damaged. In the first two years, it’s best to remove all flowers so that energy is expended on roots.

If the leaves were frosted and distorted, take extra care of the plants. Make sure they have adequate water during dry spells (but never keep them saturated), and avoid extra fertility after midsummer so the plants go slowly dormant before winter.

Here’s more about planting and care: Growing High Bush Blueberries.

Q. Having difficulty with bearberry. Doesn’t seem to thrive in gardens in Seal Harbor. Any advice? What medium should be used to plant bearberry?

A. It would be very helpful to have more info.

  • How long ago was the bearberry planted?
  • What percentage of the overall planting is affected?
  • What is the pH of your soil? (Have you had your soil tested?) Bearberry is fussy about pH: 4.5 – 5.5, similar to wild blueberries.
  • During drought, has it been watered? Even though it likes dry, well drained soil, it needs water, especially to get established.
  • Has it been fertilized? Fertilizing after mid-summer can prevent it from going dormant before winter, resulting in winterkill.
  • Is it mulched? Sometimes the plant won’t send out roots in mulch.
  • What do the roots look like? White and healthy? Dark and mushy?
  • Can you send a photo or two? One of the general planting, and a close up of the plant.

Q. How do I treat sunscald on my peach tree?

A. At this point, you’ll want to trim off any excess bark or prune out any dead branches as a result of sunscald. Sunscald is more common on young trees and a variety of deciduous trees that naturally have thin bark. White tree wraps should be used in the winter for the first several years until the bark thickens. Just be sure to remove the wrap once the night temperatures are above freezing. Also, keep in mind that you want to avoid fertilizing in the late summer or fall because that will encourage new growth at a time when your tree is supposed to prepare for dormancy.

Here is more information about Frost Cracks and Sunscald on Trees from UConn Extension.

Swiss chardQ. My Swiss chard looked lovely until one morning I went out and discovered tan patches on the leaves. Now, two weeks later, the leaves mostly look dry and dying. I’m attaching a photo. What causes this, and what can I do about it? Is there an organic solution, and can I save my Swiss chard this season or should I just pull it out?

A. We suspect you may have spinach leaf miner. Is there any way you could send me a few more photos of your Swiss chard leaves? It’s a little difficult to identify from the photo you submitted.

Q. I am wrestling with goutweed that has spread next to our wooded stream area and came across this vigorous growth (photos A and B), at the edge of the goutweed area. But also not far from another taller plant that looks like it (photo C). I’m hoping that what is in photos A and B is not goutweed, but the other plant. Can you tell from the photos, and if it’s not, what is the plant in photo C?

A. Unfortunately, I think A and B are both goutweed.

Photo C is sambucus racemosa.

To be sure, remove a leaf and see if it has the same distinct goutweed smell. That’s one of my quick ID tricks with that plant.

Q. I have a weeding job and there are substantial patches of horsetail in the perennial beds. What would you suggest? I know eradication is tough, but are there ways to keep it contained with our chemicals?

A. Horsetail (Equisetum) is an ancient native plant that many gardeners struggle to control due to its underground rhizome system. I’m afraid there is no easy answer for how to manage Horsetail. You can dig this plant up, just be sure to dig up as much of the roots as possible. If the Horsetail is established, you’ll likely need to continue this practice for a few years before you can successfully eradicate it. Persistence is key here. Horsetail thrives in wet conditions, so if you are able to improve the drainage in the perennial beds that can also help.

There are not many herbicide options for controlling Horsetail and the effectiveness of such an application is questionable. For more information, check out The Ancient Horsetail (PDF) from Purdue University and Equisetum: Biology and Management from Iowa State University.

Q. I have a small Portland yard that I’ve been slowly working on to create an ecological landscape.  I’m sure there’s a lot I’m missing, but I’m not sure if I should ask for someone to take a look to get advice, or if there are example gardens I should seek out. I’ve found the Portland Pollinator Habitat Map, but many of those gardens look more like traditional ornamental gardens to me, where I would be more interested in seeing residential gardens that mimic the look and function of nature.

A. It’s great to hear of more folks transitioning to natural-looking landscapes. Your situation is a perfect fit for our NEW garden mentor program. Click here to learn more and sign up for a mentor. Our local Master Gardener Volunteer coordinator will match you with a Master Gardener who has expertise in the gardening topics you’re interested in. Our Master Gardeners are a terrific resource and are eager to help.

Butternut squash leavesQ. Why are my butternut squash leaves turning yellow? They were planted 10 days ago. Onions were in this bed last year.

A. It’s tough to say for sure because I cannot seem to zoom in on the photo to get a good look, but it seems to be showing typical transplant shock symptoms. In a well-sited vegetable garden (full sun with good drainage), it should come through just fine if you provide it with a deep watering twice a week. I would also give it a slight nitrogen boost by putting a very small amount (1tsp) of bloodmeal scratched into the area around the plant (once).

You might want to consider mulching with straw to reduce weed competition and maintain even soil moisture. If you have row cover, this is a good time to cover your young plants to keep out the cucumber beetles. Be sure to remove the row cover when you see both male and female flowers.

Q. This happened just this morning. This weekend, I transplanted two astilbe plants from one garden to another. I water them early in the morning; went out at 6:00 AM to turn on the slow-drip hose and returned at 7:30 to move the hose. At this time, the plant had been dug up, torn apart, a hole about 6-8 inches deep, and no evidence of eating of the plant. The two other transplanted plants were left undisturbed, just three feet away. I have MANY chipmunks, but this had to have been done by something larger. Raccoon? Skunk? And for what? Grubs? Should I replant?

A. If you used an organic fertilizer with bone meal, blood meal or fish emulsion, it may have attracted any number of omnivores: skunk, raccoon, fox, even a cat or dog.

Any of those animals may also have found a beetle, grub, chipmunk or vole in the area and dug it up in pursuit.

Q. I have one greengage plum, and see curculio damage on fruitlets already. How best to control? It’s a small young tree. Pick off damaged fruits? Put a tarp under to collect drops? Other ideas? Both? I don’t have a sprayer for Surround but do have one I have used for Bt. Holds 2 gallons.

A. Sorry about your plum curculio. It’s very common in Maine.

Are you using a standard fruit tree spray in the orchard? Because of the smorgasbord of fruit trees, it may be a good measure.

This and other pest info is in our Growing Fruit Trees in Maine resource under Insect Pests.

A two-gallon sprayer will work well for most liquid sprays. Be sure to rinse the container well before and after use and follow label directions.

If you’re interested in using Surround, here’s the Label with mixing instructions.

Q. Where’s a good source for salt hay near Freeport, ME?

A. I’m not aware of businesses near Freeport that sell salt marsh hay. You’d be better off looking for this product in coastal areas of Massachusetts, New Hampshire, and very Southern Maine. The only business I know that carries this product in Southern Maine is Wallingford Farm in Kennebunk (no endorsement intended), but I have not purchased salt marsh hay from them myself so I can’t attest to the quality. Have you tried contacting your local nurseries?

Q. I am looking for several fairly low growing shrubs, that will tolerate shade and preferably flower and attract birds. I want to separate my planned shade garden from my shady wilderness.

A. I would suggest going with a Viburnum for your site, especially if you are interested in attracting birds and other wildlife. Maple-leaf Viburnum (Viburnum acerifolium) is a versatile plant that can tolerate moist to dry conditions and thrives in the shade, it gets to be about 3-6’ in height.

Here are some other options:

  • Hobblebush (Viburnum lantanoides): 3-10’, moist
  • Wild-raisin (Viburnum nudum var. cassinoides): 6-12’, wet to moderately dry
  • Rhodora (Rhododendron canadense): 3-4’, wet/moist
  • Bush Honeysuckle (Diervilla lonicera): 3-4’, medium dry

You can find more plant lists in our Plants for the Maine Landscape chapter of our Maine Master Gardener Volunteer Manual.

Q. What material should I use to cover my blueberry bushes so birds will not eat the berries but also shall not be trapped (no net)?

A. A good quality net that’s elevated above the bushes should not ensnare birds if done correctly.

From our publication Growing Highbush Blueberries:

“Birds are typically the most serious pests of blueberries. Covering the plants with netting is the most effective control. Plastic or cloth netting is available through garden supply dealers. It is best to use a post and wire frame to support the netting over the plants. This will provide the best protection of the fruit and prolong the usable life of the netting. Drape the netting over the frame just as the first berries begin to turn blue. Be sure the edge of the netting is weighted or staked to the ground to prevent birds from getting under. Remove the netting as soon as all harvesting is complete, and store it in a cool, dry place. This will prolong its useful life.”

horse tailQ: We have an aggressive weed that I believe is called “horsetail.” It is growing and spreading in my flower garden, vegetable garden, and all around the “rain garden” (created by the contractor as part of the subdivision plan). I have also noticed it growing along the main road. It appears to be quite invasive. We have tried pulling it up, digging it up, and smothering it. Nothing seems to help. Is there anything I can do to eliminate or reduce it?

A: Horsetail (Equisetum) is an ancient native plant that many gardeners struggle to control due to its underground rhizome system. I’m afraid there is no easy answer for how to manage Horsetail. All of the practices you mentioned, pulling/digging it up and smothering it with help, but it’ll take time. You’ll likely need to continue this practice for a few years before you can successfully eradicate this plant from an area. Persistence is important when handling horsetail because of its extensive root system. Horsetail thrives in wet conditions, so if you are able to improve the drainage in the flower and vegetable gardens that can also help.

There are not many herbicide options for controlling Horsetail and the effectiveness of such an application is questionable. For more information, check out The Ancient Horsetail (PDF) from Purdue University and Equisetum: Biology and Management from Iowa State University.

Fruit tee leafQ: I planted a fruit tree about 12 years ago; I was told it was a pear. I was never told I needed to have two, so I could get fruit. I would like to add another one in the hope I’ll get fruit someday. Can you tell me what kind it may be, please?

A: Unfortunately, it’s not possible to ID the variety from the leaves.

There are two types of pears, Asian and European. Be sure you choose a pollinator from the same type and a variety that has the same bloom time.

Here’s info from our publication Growing Fruit Trees in Maine.

Yes, many pears are “self-unfruitful” and need another variety nearby for pollination.

Magness, Luscious and Gourmet pears are sterile and will not pollinate other pears. Seckel and Bartlett will not pollinate each other. (If you grow these two varieties, a third will be needed.) Comice, Bartlett, and Flemish Beauty are partially self-fruitful. It may be best to plant two different trees 20 feet from your existing tree since you don’t know the variety of the one you have. Bosc is known to be a good pollinator.

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