Questions and Answers from 2015

If you have a gardening question, you are welcome to

Questions and Answers from 2015

Answers to the 2015 season’s gardening questions were provided by Tori Jackson, Extension Educator: Agriculture and Natural Resources, UMaine Extension Androscoggin & Sagadahoc Counties, and Kookie McNerney, Home Horticulture Coordinator, UMaine Extension Cumberland County.

woman weeding vegetable garden; photo by Edwin RemsbergQ: I’m new to Maine and very interested in vegetable gardening in the coming year. Do you have any literature recommendations for general gardening and resources that cater to Maine and New England?

A: You have come to the right place! The Yard and Garden section of our publications catalog includes many Maine-specific gardening resources. If you cannot find what you are looking for, just let us know!

Q: I have heard of gardeners spreading mushroom soil to enrich their own plot. Is this available in Maine?

compostA: Products sold as “mushroom soil” are simply the spent substrates used to grow mushrooms commercially. As with any soil amendment, I recommend reading the analysis before spending a lot of money, particularly for organic matter. This material is available because it is no longer high enough in nutrients to support a crop. You may be able to find it in certain garden centers, but I would not recommend it over other sources of organic matter, particularly locally made compost.

Q: I just bought a small 1.4-acre lot on the backside of Sandy Pond in Montville. Can you tell me the USDA zone for here?

A: Based on the Plant Hardiness Zone Map of Maine, you appear to be in Zone 5a.

oak leavesQ: The many oak tree leaves on our property remained green longer than usual this fall, turned gold quite rapidly once they started to turn and now are dropping off the trees much faster and earlier than usual (the oak trees are almost bare whereas in the past they just trickled off the trees during the early winter). Does this mean anything in regard to the upcoming winter?

A: The changing of the leaves and when they fall from the tree are directly related to past and current conditions, but not to future ones.

Q: What can I spray on my garden this fall to prevent so many weeds?

Plastic mulch with straw mulch between rowsA: Dealing with weeds is probably the most frustrating aspect of gardening, but I do not recommend herbicide in a home garden. There are steps you can take now to reduce weeds next season, such as removing all existing plants from your garden (which is easier once they have been killed by a frost) and placing them in a compost pile or another location away from your garden site. It is too late this year to plant a cover crop, which can prevent erosion over the winter and out-compete spring emerging weeds, but you can cover your garden with a heavy landscape fabric and pin it down on the edges to protect your topsoil. In the spring, consider mulching around your plants and in the walkways to prevent weed emergence and commit to managing young weed seedlings as they emerge on a daily basis. Young weeds are very vulnerable and can be easily killed with a hoe or flame weeder. If you are dealing with particularly noxious weeds, you might consider moving to a raised bed system that is easier to manage. The type of weeds you have should also inform your control measures.

Q: My green beans got frosted this morning, with quite a few beans still on the plants. Now what? Is it safe to eat these frosted beans, or not safe? Should I discard them?

green beans; photo by Edwin Remsberg, USDAA: It depends. Were they just frosted, or did they freeze? Temperatures were very low last night and many locations experienced a hard freeze. Freezing and subsequent thawing damages the structure of plants, making the edible portions “mushy” and making them vulnerable to secondary infections by fungi and bacteria in the environment. If this is the case, I recommend not eating these beans. If you were spared temperatures much below 32 degrees and your beans appear to be intact (still firm, green, etc.) I recommend harvesting and consuming soon. Damaged produce, even from a light frost, does not store well. When freezing vegetables, blanching is required to stop metabolic processes and prevent breakdown. A frost or freeze before blanching means the beans will not hold up in the freezer.

Q: This isn’t a veggie gardening question per se, but it does relate to my ability to grow vegetables. I have a legion of voles living in my yard and they have no real predators in the area. I had the thought that perhaps I could go get some garter snakes from my parents’ farm in Machiasport and bring them here. Would that be a good idea, or would it be bad to introduce a completely new critter to the area?

garter snakeA: Voles, moles, and other small mammals can sometimes be a nuisance in managed landscapes, but it is not a good idea to re-locate other species to your property to control them. On their website, the Maine Department of Inland Fisheries and Wildlife says, in regards to snakes specifically, “It is environmentally unsound to capture snakes and try to relocate them on your property or keep them as pets. Due to their well-developed homing instincts, most snakes will soon leave an unfamiliar area; predators or cars often kill them as they try to return to home ground.” But it also includes tips for attracting snakes to your property.

The first step is for you to positively identify the animals causing the damage to your garden. Got Pests? from the Maine Board of Pesticides Control includes several publications that can help you do that. Coexistence is the ideal solution, but it means protecting the trees and plants that you value with hardware cloth. Vole populations fluctuate over time, so it may be that your area is experiencing a peak now. For more specific information on how to manage conflicts with wildlife, please contact Maine Department of Inland Fisheries and Wildlife.

Q: How can I get rid of Bishop’s weed? Any suggestions would be greatly appreciated.

Goutweed (Aegopodium podagraria); photo by Leslie J. Mehrhoff, University of Connecticut,

A: Bishop’s Goutweed (Aegopodium podagraria) is a very aggressive weed and it may take several years to get a handle on the population on your property. The first step is positive identification. You can see photo and read more about this plant on the Invasive Plant Atlas. The Maine Natural Areas Program lists this plant as an invasive species in Maine. (You can read more about many invasive species in Maine in the Maine Invasive Plants series.) For new infestations, cover the patch with thick black plastic in the spring as soon as new growth appears. Lay plastic on an area larger than the patch and secure edges with sandbags, bricks or ground staples. Leave for a full year. New infestations should be treated rapidly before an extensive root system is established. Hand pull and grub-up all stems, roots, and rhizomes. Bag all plant material and allow to sit for one week before disposing in a landfill. Re-check the site each year for any new growth.

Q: We planted carrot and spinach seeds on October 2nd (half are in a hoop house, half are outside). When should we mulch?

carrotsA: Spinach and carrots for a fall harvest are planted anywhere from six to ten weeks before a hard frost is predicted. Your crops under the hoop house should be available for winter harvest. When planting to overwinter carrots and spinach you may mulch them any time after germination. Mulching will protect against frost and weeds (while they are still able to grow). Your crops in the hoop house may not need to be mulched at all. If overwintering these crops, remove any mulch as soon as the snow has melted.

Q: When using milky spore to eliminate Japanese beetle grubs in my raised beds, should I till the soil, apply spore and till in, and then water? What is the order of application? Is there a “chicken safe” treatment/spray for Japanese beetles on ornamental and fruit trees? I have free-range chickens that nibble on my plants/trees/lawn, so I don’t want to use anything poisonous. I tried SAFER spray and the beetles didn’t even blink! Also is it okay to use “hose end” oil for moles on lawn areas at the same time as applying spore?

free range chickensA: A great deal of research has been done on the efficacy of Milky Spore. In Maine, soil temperatures are too low for the milky spore to take hold and affect the grub population. Due to your concern for your chickens, you may want to try beneficial nematodes for your grub problem. The best time for application of nematodes is the last few weeks in August or first few weeks of September. You can also handpick the beetles and throw them in a can of soapy water or use row covers to protect against the beetles while they are actively feeding. This is not practical for your tree but can help with other ornamental plants. For more information, see Bulletin #5037, Japanese Beetles. For your mole problem, contact the USDA Wildlife Service for assistance.

Q: How can I prevent cedar roots from invading my raised bed vegetable gardens? I’ve tried placing plastic sheeting on the ground beneath the beds, but still have to dig out the boxes and put in new soil every 2-3 seasons. Cutting the cedar hedges is not an option, nor is moving the raised beds because of the small size of my yard.

roots in garden soil
Photo by Gerald Holmes, California Polytechnic State University at San Luis Obispo,

A: Tree roots just can’t resist soft soil, such as that which is found in raised beds, with lots of nutrients and plenty of water readily available to them. Sadly, tree root competition for these elements is generally successful. The smaller root systems of annuals and perennials, hard as they try, can’t out-compete tree roots. You can line the bottoms of the beds with hardware cloth topped with weed barrier. This not a permanent solution, though. Because you are unable to move the beds and do not want to cut down your cedars, you will most likely continue to have this problem. Tree roots can extend one and one-half times the diameter of the canopy (farthest ends of the branches). It is understandable that removing the soil every 2-3 years is difficult, but the tree roots will always win out over plants with much smaller root systems.

Q: I would like to use straw as a mulch in my vegetable garden in Aroostook county to create a no-till and hopefully weed-free garden that would encourage moisture control and worm activity. My concern is whether or not the local straw from oat/barley harvests would have any residual herbicides that could harm future annual vegetable plantings.

barleyA: Herbicide carryover is a concern to all home gardeners. In the state of Maine, the hay and straw from pastures that have been treated with herbicides containing aminopyralid, clopyralid, aminocyclopyrachlor, and picloram cannot leave the farm from which the field was treated for 18 months. The same is true for manure. There are warnings labels (which are legal documents) on these herbicides, which state that the by-products harvested from treated fields must stay on the producing property. It is always a good idea to inquire with the seller of the straw, what herbicides may have been applied and when. The Maine State Board of Pesticides Control has released a state of Maine warning about persistent herbicides in response to findings about persistent herbicides. It would be against the law for anyone to knowingly sell you a product that had been treated with any of the herbicides listed in the document.

Q: I have an area that is wet most of the year. I’d like to plant something edible there. Any suggestions?

rows of lettuce plants; photo by Edwin RemsbergA: There are very few edible crops that grow well in persistently wet conditions. The question would be exactly how wet is the area and does it ever dry out, and how many hours (if any) of sunlight does it receive? If the area never dries out, then the only crop that may grow there would be Nasturtium officinale, watercress. If the area does dry at times, many varieties of lettuce can be tried, as well as arugula, again depending on the sunlight.

Perhaps the installation of a rain garden would be a better alternative for your damp area. Rain gardens improve the quality of lakes, streams, and ponds by filtering harmful runoff. Learn more about the benefits of a rain garden in Bulletin #2702, Landscapes for Maine: Adding a Rain Garden to Your Landscape.

Q: I live in Alton and since late August until now in mid-September, the grass on my lawn has had black tips that are dusty, sooty, and oily. When I walk across the lawn, my flip-flops and feet become covered in a black, sooty/oily mess. Powdery puffs spring up around my feet as I walk. Is this black slime mold? I have never in over 30 years had this on my lawn and am unfamiliar with this strange and disgusting problem. The grass is not high, but I am thinking about mowing it anyway to try to get rid of the mess, but will mowing just spread the mold and make things worse?

leaf blade infected with Ustilago striiformis
Leaf blade infected with Ustilago striiformis.

A: From your description, your lawn may have the fungus Ustilago striiformis, more commonly known as smut. This fungus overwinters in lawns and is a systemic perennial infection. Spores are disseminated by wind, water, equipment, people, and animals, so do not mow while the spores are active. The disease is not apparent during hot temperatures but will be activated as soon as the temperatures begin to cool in the fall. Smut is favored by high nitrogen conditions. Do not fertilize your lawn now, and in the future avoid fertilizers that are high in nitrogen. Reducing drought stress will also go a long way towards keeping the fungi at bay. Chemical fungicides will only temporarily suppress the disease. Good cultural practices are the best means by which to keep the fungus controlled going forward. Here is some very helpful information on Ustilago striiformis (PDF) as well as how to maintain a home lawn in Maine. It would be advisable to get a complete diagnosis of the problem, by submitting a sample to the UMaine Extension Plant Disease Diagnostic Lab in Orono. How to submit a plant sample for a full diagnosis.

Q: I am tending some school gardens in Waterville, Maine, where we are going to try our hand at planting a fall greens garden with our garden club during the third week of September. I realize it’s getting late in the season, but we are going to put up hoop houses and hope our unseasonably warm weather sticks around! The raised bed I want to plant currently has a layer of hay on top of it that is slowly decomposing into the soil. Should I turn that hay into the soil? Should I remove it entirely and add it back when I put the beds to rest for the winter? Should I plant my seeds underneath the hay as is? Also, what do you recommend for winter cover crops in raised beds?

raised bed garden plotsA: Hay is more likely than straw to contain weed seed, but if you are fairly certain that you purchased high-quality hay, you can incorporate it into the soil now. Organic matter that is not fully composted, is best tilled under to a depth of 6 inches. In the Spring there will be lots of wonderful nutrients available for your plants right at the root zone. You may also use the hay alongside the rows of your planted seeds to help maintain the soil temperature. Do not cover the seeds with the hay, as it may inhibit germination of tender winter greens. I recommend an excellent publication from UMaine Extension that contains a variety of effective methods for Extending the Garden Season.

There are many appropriate cover crops that can be used in raised beds. Some of the best include winter rye, hairy vetch, and crimson clover. See Protect and Improve Your Soil with Cover Crops (PDF) for a comprehensive list of winter cover crops.

Q: I’m hoping for a lawn pest I.D. We don’t know what critters might be to blame. We have a healthy lawn one day, then many 3- to 4-inch-long, 2-inch-wide strips/divots in the lawn the next day. The ground feels squishy underfoot.

A: Many animals will dig in lawns to find food that lies below a lawn surface. Raccoons and skunks are very likely to exhibit this type of behavior. A good test would be to turn over a portion of the damaged lawn to inspect for pests. A very likely candidate would be a white grub. There are many types of white grubs, which are the larval stage for a variety of insects, such as European Chafers, Rose Chafers, and Japanese Beetles. Another pest that causes similar damage in lawns is Chinch Bugs. Given the type of damage you are describing, the Japanese beetle (Popillia japonica) grubs are the likely reason that you are finding divots in your lawn. The squishiness in your lawn is caused by the grubs eating the lawn roots. Beneficial nematodes have proven to be effective, but the best time of year to apply them in Maine is late August.

Holes dug in the lawn (left) and white grub (right) under the lawn.
Left: Holes dug in a lawn by a skunk. Right: A white grub found beneath the same lawn.

Q: On a walk to the Owl’s Head Lighthouse on September 14, 2015. There were many tall bushes with beautiful pink flowers. What is this plant? The flowers look a bit like the bloom of penstemon.

A: It is difficult to identify any plant without either very clear photos, preferably with closeups of the various plant parts, especially the flowers, or an actual sample of the plant. If you are able to provide us with this, we can very likely identify the plant for you. If the plant is on public lands, then you should not pick it. If you wish to submit a plant sample for identification, you may contact your local UMaine Extension county office for assistance.

Q: I have a Camperdown elm with a bark wound approximately 2 inches from the ground. What would be the best treatment products/procedure?

A: Bark wounds damage a tree’s food and water-conducting tissue. If the bark is wounded around more than 75% of the circumference of the tree, then the tree may not be able to survive. If this is not the case, the good news is that otherwise healthy trees have their own mechanisms for deterring decaying organisms, insects, and diseases.

There are two primary methods in which a tree heals itself. The first is compartmentalization. The injured tissue does not heal but is sealed by “callus” tissue (new wood), which forms around the edges of the wound. This “callus” tissue forms a protective barrier, preventing infection and decay.

The second method is the formation of barrier zones. The tree will release chemical and physical boundaries that make the wood undesirable to disease and decay organisms.

Wound dressings such as tar or paint do not prevent decay and can interfere with wound closure by

  • preventing the drying of the wound and encouraging fungal growth.
  • interfering with the formation of the “callus” tissue.

Healthy trees can recover quickly from tissue wounds. Remove any ragged bark edges from around the wound with a very sharp knife, taking great care not to affect any healthy bark or expose more live tissue. If possible, the wound should be shaped like an elongated oval, with the long axis running vertically along the trunk or limb. Keep the tree vigorously growing. Be sure to water during periods of drought or low rainfall and fertilize properly. Following these steps, your Camperdown Elm will be able to heal itself.

Wild Mushroom Warning

wild mushrooms
Wild mushrooms: The consequences of making a wrong guess or misidentifying an inedible mushroom for an edible mushroom can be severe, sometimes resulting in serious illnesses and even death.

We have received a number of questions recently about wild mushrooms. Warm and persistently damp weather has likely contributed to their emergence.

There are many good reasons not to pick and or eat mushrooms that grow in the wild. The consequences of making a wrong guess or misidentifying an inedible mushroom for an edible mushroom can be severe, sometimes resulting in serious illnesses and even death.

One of the dangers of collecting mushrooms in the wild is that there are toxic look-alikes — poisonous mushrooms that resemble edible ones. Social media has contributed to the rise of poisoning due to wild mushrooms. People are eager to forage for wild foods, but looking up a photo on the Internet will not guarantee you have collected the non-toxic variety. Even some experts are not able to distinguish between certain varieties of mushrooms unless they are placed under a microscope and their spores properly identified. It is never advisable to eat a wild mushroom that has not been properly identified.

If you are still interested in learning how to forage for food and mushrooms, here are a few first and very practical steps to follow.

  1. Join a local mycological (fungi) group.
  2. Buy a respected regional field guide to learn what mushrooms grow wild in Maine.
  3. Seek to conclusively identify at least the genus of the mushroom you have found (using the key in your field guide identify the stem, a spore print, what the mushroom is growing on, and the stem base).
  4. Dogs are the number one victims of wild mushroom poisoning. Think twice before taking your dog on a wild mushroom forage.

Q: I am wanting to grow a fall “greens” garden in the school raised bed gardens where I volunteer. What sort of greens would you recommend planting at this time of year and how should I care for them? I have materials to make hoop houses over the beds to help keep them comfortable.

A: We are very fortunate that there are many crops that will grow well in the fall and even some that with the proper protection can possibly survive longer.

Here is a short list of crops that can grow well in Maine for fall, but start your seedlings now if already haven’t.

  • Cool cole crops such as kale. Many varieties can even take a light frost.
  • Collards are very hardy.
  • Many Asian greens grow well in the cold: mustards, mizuna, and pac choi.
  • Greens such as endive, escarole, radicchio, and especially spinach. Plant spinach in the fall and after harvesting to tender leaves, it will go dormant.
  • Chard often survives winter freezes.
  • Plants with deep roots such as leeks, carrots, parsnips, beets (edible greens), and turnips.
  • Many lettuces and parsley.

Bulletin #2752, Extending the Gardening Season includes many tips to help you extend the growing season.

Q: I have a 3-acre lawn. The soil is clay-based and apart from this year, it is always moist, resulting in a lawn that has to be mowed every three days to keep it under control. However, another plant that likes this combination is Glechoma hederacea. I have massive patches of it that have choked out the grass and has become a tiring nuisance. I have to constantly weed the edges of our flower gardens to keep it from taking over. Do you have any successful ways of eradicating this ‘Creeping Charlie’?

Ground ivy (Glechoma hederacea L.)
Ground ivy (Glechoma hederacea L.). Photo by Leslie J. Mehrhoff, University of Connecticut,

A: Glechoma hederacea is a very difficult weed to control. This plant was introduced in the 1800s as a medicinal and ornamental species. Your clay soil and moist conditions are perfect for ‘Creeping Charlie’, but it can also adapt to dry conditions as well. Mowing frequently, such as you have been doing, can keep the plant from spreading by seed. It still can travel aggressively by vegetative runners. Small patches can be hand dug out, but care must be taken to remove all of the stolons and roots. This will work for your flower beds, but from your indication, the areas in your yard are too large. Glyphosate is an herbicide that will help control Glechoma hederacea, but great care must be taken when using it. Do not use glyphosate within 25 feet of water or watersheds. Read the label carefully and follow all application instructions.

Here are some tips that will help you Maintain a Healthy Lawn in Maine.

Q: This is about our high bush blueberries. This year’s crop is not as flavorful as in past years and the berries are soft and squishy even before they are ripe. We live in New Vineyard in Franklin County. Our plants are 25 to 30 years old. They have done well in the past, but this year we are losing about half our crop. We checked with my wife’s parents, who live in Windham and they are experiencing the same thing. Any thoughts? We do water them when we haven’t had enough rain.

Stages of Blueberry maggots: larvae; fly; comparing male and female abdomensA: The cause of your soft squishy fruit may be Blueberry maggots. Adult flies lay their eggs under the skin of green and ripe berries. The tapered maggots feed on the fruits for about 20 days, causing them to turn soft and mushy. The maggots then drop to the ground and the pupae overwinter in the soil and then emerge as small flies the following season.

For a positive I.D., send a sample of the fruit to the UMaine Extension Insect Pests, Ticks & Plant Diseases lab in Orono. See How to Send a Plant Sample for instructions.

If Blueberry maggots are the problem, they can be managed in future seasons with appropriate insecticide sprays applied when the fruit begins to color up or with traps baited for Blueberry maggot.

For more information, see UMaine Extension’s Monitoring for Blueberry Maggot.

Q: I have a beautiful moss garden, which I have tended carefully. I am in Lubec, and the moss is shaded by some large maple trees. This summer I notice some odd growths (fungi?) in the moss. They are flat to the ground, purple/black, round with scalloped edges. The edges are white. Can you identify this? Is it harmful to the moss? Should I do anything to discourage it from growing here?

A: Although your description of the fungi in your moss garden is quite clear, it is nearly impossible to identify without either a close-up photo or an actual sample. For identification, submit clear photo(s) or actual plant samples to your local UMaine Extension county office. Recent warm and persistently damp weather likely contributed to the emergence of the fungi.

Q: I live close to active clamming flats in Cape Elizabeth and do not want to use grub-killing poison in my grass, but I have had a serious Japanese beetle problem for several years. The last two years I had to replant my entire front yard because the skunks and crows dug it up for grubs. I let them feed to their hearts’ content, but it did not solve the issue. I have tried Milky spore three times over two years. I tried beneficial nematodes without success too. I put up a bluebird feeder and bluebird box to attract grub-eating bluebirds (though they never did attract bluebirds). I hand-pick the adult beetles from my bean and raspberry plants. I don’t think I should plant my front yard with plants other than grass because it is my septic leach field. I try to let my front lawn go dormant in summer as well, though the leach field and shade make that a little difficult. Are there other organic solutions for this really tough issue with my front lawn?

Japanese Beetle
Japanese Beetle

A: It is wise to be cautious regarding the use of chemical pesticides and herbicides so close to waterways and in particular to a commercial fishery. Japanese beetles are difficult to control but can be managed. Attacking the grub stage will provide the best results. You have tried many of the suggested remedies. Nematodes are best applied during the last 3 weeks of August. They are living organisms and are temperature sensitive. They also must be well watered in.

Chemical lures generally attract more beetles to your yard, thus perpetuating the life cycle. Hand-picking can help and should be done frequently during their feeding period. Mornings are best, when the beetles are less active. Removing or transplanting some of the plants that are most attractive to the beetles (roses, berries, grapes) can also help. For more information about managing this pest, see Bulletin #5037, Japanese Beetle.

Q: I grew broccoli for the first time this year and my plants got big and leafy, developed a tiny head (slightly bigger than a golf ball), and then started flowering almost right away. It was not a super sunny spot, but I thought it was sunny enough, given how the leaves got so nice and big. I watered pretty frequently. Is my problem the sun or the soil? I was quite puzzled that something that looked so great early on did not work out at all.

broccoliA: There could be many reasons why your broccoli did not produce large heads. Broccoli is considered to be a cool-weather crop and will bolt (begin to flower and go to seed) if the temperatures are too warm. Therefore, the timing of setting out seedlings is very important. It is best to set out broccoli seedlings in early spring 1-2 weeks after the last frost.

Broccoli does prefer 6-8 hours a day of sun and should be fertilized 1-2 times before head production begins. Correct spacing between plants, 1 1/2 – 2 feet, is very important for nutrient uptake, as is regular watering. Choosing varieties that perform well in Maine will also help ensure your success. See Bulletin #2190, Vegetable Varieties for Maine for suggestions.

I suspect that our recent hot, wet spell caused your plants to not produce well. Homegrown broccoli is worth the effort. Try again next year and start earlier and you will be rewarded. A soil test will also let you know about any deficiencies in the soil that may hamper the growth of broccoli. Soil test kits are available at your local UMaine Extension county office.

Two additional resources that you might find helpful: Bulletin #2286, Testing Your Soil (from UMaine Extension) and Growing Broccoli (from University of Illinois Extension).

Q: When is it the right time to transplant strawberries? My friend has a prolific crop of strawberries and wants to divide them and give me some.

strawberriesA: The best time to transplant strawberry plants is immediately after they are done fruiting, usually by late July. If your friend could wait until next year, that would be best, but you may still be within the timeline to get them established before the first frost (always unpredictable). If your friend does decide to transplant, be sure to watch for an early frost and protect the new transplants with a row cover or some other insulating material.

Q: It appears that my tomatoes have been affected by late blight, maybe early blight, too. I previously had lush tomato plants, prolific in output, and the last two years, NOTHING. Early yellowing of leaves, dropping off, and the same late in the season with very little production. What can I do? I add rich organic compost every spring; I plant strong seedlings that I start myself. I feed and add calcium, manure, and organic tomato feed. Still NOTHING! Is there a way to revive or heal the soil, if it is infected? Also, should I use a cover crop? All my beds are raised beds. I have 10 beds and have spent a lot of money in building them, adding soil, and upkeep. Will a cover crop help the above or should I be “putting them to bed” with a cover to heat them up?

A: Sorry to hear that you are having such difficulties with your tomato plants. Both early and light blight have been detected and reported in Maine this growing season. It has been a difficult tomato growing season in Maine and the conditions that cause both diseases to activate have been present. It would be important to determine which disease it is and best if you could send a sample of your tomatoes to the UMaine Extension Insect Pests, Ticks & Plant Diseases lab to Orono for positive identification. See How to Send a Plant Sample for instructions.

Early blight Alternaria solani germinates at a wide range of temperatures. When temperatures are 80-85°F, the spores can germinate in less than a half an hour and totally infect the plant within two days. It is important to note that these spores live in dead plant debris. Good garden sanitation is key.

Late blight develops in live host tissue only and is a much more serious disease. Infected plants should be removed from the garden and destroyed. Do not compost these plants or till them under. Remove any volunteer nightshade plants, such as potatoes.

By all accounts, it sounds as if you have done all the right things necessary to have good healthy plants. The disease has had very favorable conditions this year. The only other question would be, “Was the manure fully composted?”

See Bulletin #5087, Early Blight of Tomato from UMaine Extension and Late Blight on Tomato from Cornell University for more information about these diseases.

winter rye
Winter rye used as a cover crop; Texas A&M AgriLife photo by Dr. Todd Baughman

There is absolutely no downside to planting a cover crop in your raised beds. It will strengthen the soil, help add nutrients (both macro and micro), and help soil structure. See Cover Crops for Home Gardens (PDF), Cover Crops for the Home Gardener, and Cover Crops for Season’s End for more information about the best cover crops for Maine gardens.

Q: We have a small crab apple tree that has been infected with cedar rust. Our neighbor has the same on her trees, and she is going to cut them all down, fearing the rust will spread. Is that necessary? Is there a treatment for the tree and/or for the soil that will prevent or treat cedar rust?

cedar apple rust spots on leaf
Orange or yellow spots on the upper leaf surface are symptoms of cedar apple rust.

A: Cedar apple rust (Gymnosporangium junipera-virginianaepress) requires two hosts to complete its two-year life cycle. One host is a member of the cypress family and the other is a member of the rose family, most often affecting apples and crab apples. This disease is not considered life-threatening to either host. The disease begins on the cypress host and appears as tan or brownish galls in the winter and early spring. Moist weather in spring causes the galls to swell, releasing the spores. In late spring, bright orange leaf spots will develop on the upper surfaces of the leaves of the apple or crab apple. The disease is more unsightly than dangerous and is only considered problematic for commercial apple growers. Crab apples will not infect other crab apples and cypress will not infect other cypress. Both species must be present for the disease to develop.

There are some steps you can take to control the disease.

  • If only a few plants are involved, removal of the galls from the host cypress in late winter is beneficial.
  • Applications of protective fungicides starting at the bud break stage of the crab apple can be helpful.
  • There is no repeat of the disease cycle on the crab apple after first appearance, so spraying after the disease has presented is ineffective.
  • Use crab apples with genetic resistance to the fungus.
  • Do not plant cypress species in the immediate proximity of crab apple. It is noteworthy that the spores of cedar rust can travel a long distance.
  • Knowing that the disease is not fatal to the plant, try to live with the disease cycle.

Below are links to publications that should prove helpful:

Q: We have a 13-acre parcel south of Waldoboro on the Medomak, about 10 to 15 feet above the high tide mark, and mostly densely forested with pine trees about 50 years old. We plan to ask a certified forester how much we can thin it out (it’s on a promontory, so mostly within 250 feet of water), but in general, we want to replant with native species and create a small garden, for veggies, herbs, and some annuals and perennials. We plan to take soil samples to our local Extension office to test acidity levels, but we were wondering about the use of wood chips as mulch, as we have a lot of trees to trim and limb and would like to recycle what comes down and not just create huge brush piles. Can you direct us to any fact sheets about the use of wood-chip mulch or give us any ideas on using it constructively on our land?

Chipped wood mulch
Photo courtesy of USDA Forest Service Southern Research Station Archive, USDA Forest Service, SRS,

A: The products created from thinning and pruning in your woodlot can vary depending on the kind of equipment being used to process the trees and branches. Particle size, species mix, and whether your final material contains bark and/or wood all make a difference in what it is called and what it is best used for. Wood chips (1-2″ in size) are a highly sought-after mulch in perennial beds and shrubs, between raised beds, and in permanent walkways of any kind of garden. Commercial growers commonly use wood chips or bark mulch in raspberry and highbush blueberry production to inhibit weed growth and conserve water around plants. These fact sheets from the Colorado State Master Gardener Program go into more detail about appropriate use of mulches, including wood chips. When used on the soil surface, wood chip mulch does not tend to tie up too much nitrogen, but when incorporated, the very high C:N ratio could become problematic for plant growth, so be sure not to incorporate the wood chips into the soil in an area where you are growing your vegetables and herbs, and stick to mulches like straw under those plants. If you have more than you can use in a few years, I’m sure your gardening friends and neighbors would love to hear from you!

Q: My tomatoes are splitting as they ripen. What is the cause? Should I pick them early and let them ripen on the windowsill?

tomatoes cracking as they ripen on the vine
University of Nebraska Institute of Agriculture and Natural Resources photo.

A: Tomatoes split and crack in response to uneven watering and/or when they ripen quickly in hot weather. If you do not water your plants regularly and they are allowed to become dry as fruit are nearing ripe, one good thunderstorm can cause the fruit to crack as they take up a lot of water all at once. The inside of the fruit grows more quickly than the skin of the tomato and this causes it to crack. Certain varieties are more prone to cracking than others and you may be seeing it in the last few weeks as fruit are ripening in particularly hot weather and with intermittent (and sometimes, heavy) rain. Harvesting them early will prevent the cracks, so, that may be a good option for you this year. In the future, planting varieties that are less likely to crack (like Jetstar), heavily mulching with straw under your plants, and using drip irrigation to maintain consistent soil moisture will go a long way to preventing cracking. Once fruit have cracked, it is important to harvest them soon so that secondary infections do not ruin your tomatoes. Cracked fruit may not be pretty, but they are still fine to use as long as they have not begun to rot. You can read more about and view photographs of Common Tomato Diseases and Disorders on the Got Pests? website maintained by the Maine Department of Agriculture, Conservation and Forestry.

Q: I have a newly hydro seeded lawn that I watered faithfully, but crabgrass has taken over. I am looking for a natural way to kill it. I have seen articles about using baking soda. Can you advise if that will also kill the grass? Or should I weed the whole lawn and overseed in September. I really don’t want to use chemicals. I use a lawn service, so that may be a factor too.

A: If your lawn is new, you should be able to get an analysis of the seed mix that your lawn company used. Have you asked for that? I also recommend getting your grass(es) identified before taking any measures. Many mixes contain species like annual ryegrass so that you have the “instant lawn” effect in year one. Those species will not survive the Maine winter and your long-term grass species will actually be something else. Is it possible that what you are seeing is not crabgrass, but one of these fast-growing annuals instead? I almost never recommend herbicides in a home landscape, even if they are a seemingly “safe” material like baking soda. When applied improperly, or at a high rate (like on an entire lawn!), virtually any material has the potential to damage non-target organisms in your soil, wildlife, and ground or surface water. If, after properly identifying your grass species, you have determined that you do have weedy types, you should speak to your lawn company about their warranty. We are entering the best time of year to renovate and establish lawns in Maine. You, or your company, should follow the guidelines outlined in Bulletin #2367, Establishing a Home Lawn in Maine, Bulletin #2243, Maintaining a Home Lawn in Maine, and Bulletin #2166, Steps to a Low-Input, Healthy Lawn. If you would like help identifying the grass species in your lawn, you may submit digital photos or a physical sample to your local UMaine Extension office. Please be sure to include some grass plants in flower, as this is the best way to ID any plant.

Q: I need help diagnosing a problem in our vegetable garden. The pepper plants bearing fruit are falling over and the section of stem that comes in contact with the soil is completely withered and brown. The plant above the soil looks healthy and robust one day and then is fallen over and completely wilted the next. Is this Fusarium wilt? If so, I know I’ll have to dispose of the plants and that other nightshades could be affected. I have sterilized my tools. How do I treat the soil in this raised bed now?

Fusarium Pathogen: Macroconidia (on pepper plant)
Fusarium Pathogen: Macroconidia (from pepper plant). Photo by Bruce Watt.

A: Based on your description, it sounds like your peppers are succumbing to either Fusarium wilt or Verticillium wilt, whose symptoms can be as sudden as you have noticed, particularly when plants are laden with fruit.

If you would like a definitive diagnosis, you may submit a plant sample to our diagnostician in Orono per the instructions here.

Rotating away from all solanaceous species (pepper, tomato, potato, eggplant, etc.) for 4-6 years is one management strategy I recommend. Deep cultivation and solarization using clear plastic may also help remove the disease from your soil, though you will also damage soil structure and kill “good” soil microbiota in the process. In the future, choose varieties with resistance to these diseases. They will be labeled V (for Verticillium) and F (for Fusarium) resistance.

In the meantime, dispose of any plants impacted. Do not put them in your compost pile, as it is very unlikely to get hot enough to kill this disease and you could end up spreading it to other areas of your garden.

For more information, including photos, I recommend Fusarium and Verticillium Wilts of Tomato, Potato, Pepper, and Eggplant from The Ohio State University Extension.

acornsQ: It’s August 2015; why are the acorns dropping so early and why are they are so small?

A: An early acorn drop likely means that the oak trees are stressed in some way and that they are aborting a portion of the crop for the sake of the overall health of the tree. It is also possible that the smaller, green acorns were not pollinated due to unfavorable conditions during bloom. Acorn production varies from year to year and tree to tree. This is likely not indicative of a serious, long-term problem. I expect we will still see plenty of normal, mature acorns drop this fall.

Q: I have an overabundance of freshwater mussels in my pond. If harvested and tilled into my garden spot, would they provide any nutrients to the soil?

Zebra mussel on native mussel
Zebra mussel on native mussel

A: All living creatures contain nutrients that could be valuable to your soil and the plants growing in it. Mussel shells contain many micronutrients, and of course, calcium, which can be difficult to get in other forms in a home garden. I recommend adding seafood shells to your compost pile, not directly to your garden. The challenge with shellfish is that the particle size needs to be relatively small to be broken down and utilized by the microorganisms in your compost and soil. This article from Cornell University on composting zebra mussels includes a compost recipe you may wish to try.

Q: My tomato plants are huge, bushy, and very healthy in appearance. They have blossoms and some are starting to set fruit, but I feel like I should have more blossoms and fruit by now from such large, robust plants. The tomatoes were planted and side-dressed with plenty of compost at transplanting time, but I have only fertilized once this season with a seaweed/fish emulsion fertilizer. Is there anything I can do right now (late July/early August) to encourage my tomato plants to set more blossoms and fruit? I try to stay completely organic and do not use chemical fertilizers.

Extension expert demonstrates how to stake tomato plants using a trellis
Mark Hutton, Extension Vegetable Specialist, with tomato plants staked on a trellis.

A: Are your tomatoes determinate or indeterminate? Indeterminate varieties need to be staked and pruned (YouTube video), while determinate varieties can remain bushier and grow on their own, but can also benefit from basket weaving. Plants that are very dark green and vigorous may be over-fertilized (too much nitrogen), which can cause a plant to become primarily vegetative. Flowering and fruiting can be induced by placing a bit of stress on your plants. I recommend discontinuing fertilizer and pruning out suckers.

Q: If I use a salt, vinegar, and water solution to get rid of weeds in my flower garden, what will that do to the soil around it? Will it kill my flowers too? I am trying to spray it only on the plant, but am worried some of it will get into the soil, too. I have a ton of goat weed running everywhere and can’t seem to get rid of it. Any suggestions?

A: It is likely that the salt and vinegar will impact non-target plants and soil organisms in your garden as well as the weeds. I do not recommend the use of any kind of herbicide in a home garden. Hand-pulling and mulching are the most effective and least risky methods of managing weeds. This article from the June 2010 issue of the Maine Home Garden News, There’s More to Weeding than Meets the Eye! Cultural Weed Control, goes into more detail and should give you some useful tips for managing your flower gardens.

Q: We’ve had our red maple tree for about 5 years. The leaves on one section are curling and overall it doesn’t look healthy. We have kept it watered since the last soaking rain. Our other trees on the property seem fine. What type of bug or disease might it have? Or is it just a water issue?

Red maple
Red maple. Paul Wray, Iowa State University,

A: It’s been a rough few years for maple trees as fungal diseases, high humidity, and uneven water have reduced vigor of trees throughout Maine. The early warmth this spring, followed by cooler, damp weather caused many maples to put out a large quantity of seeds and reduced leaves, giving the appearance of weakness. I do not suspect that your tree is suffering from drought stress, particularly as all of your other trees seem fine. There are several insects that will cause maple leaves to curl, including aphids, mites, and midges. Most will not cause lasting damage to a tree. If this is a high-value tree in your landscape, you can send samples of the affected leaves to your local Extension office, or directly to the Pest Management Office in Orono. A diagnosis will be made to determine if it makes sense to treat the tree for an insect or disease.

Q: My question is less about growing things than it is about the bugs that live in the garden. My 3-year-old granddaughter was playing near our pumpkin plants and dug up some mud with a kid’s plastic shovel. She was immediately stung by what looked like a yellow jacket. Within seconds there were dozens of the angry little critters all over the mud and shovel, as she screamed in pain in my arms. A half-hour later they were still buzzing around the shovel and the mud. What are they? Where did they come from? And how can I make sure they are not in her play area?

A: There are several species of ground-dwelling wasps and bees in Maine that your granddaughter may have inadvertently disturbed with her shovel. I cannot say for sure which species it is without a sample, but yellow jackets (particularly, eastern yellow jackets) will sometimes build their nests underground. I recommend sending a sample to the pest management office in Orono for an ID. Management will depend on which species you have. For now, people should stay clear of this area, especially if they are allergic to stings.

Q: I have blight in my garden in Sumner, Maine, and have had it since 2009. I looked at your examples of late tomato blight and that is close to what I see — black rot appears on the end of the tomato first and some of the leaves of the plant turn brown. Many other plants and vegetables have also been affected: squash, pumpkins, and beans. How can I eliminate this? I’ve cleaned up my garden and planted less each year, as well as stopped using my compost and started using commercial fertilizer.

A: Late blight, which only impacts plants in the Solanaceae family (most notably, tomatoes, and potatoes) cannot overwinter in Maine, so even though many people did have late blight in their gardens in 2009, it is not the disease you are seeing on all of the plants in your garden each season. (We do expect to see it this year since it has been confirmed in NY and VT in the past few weeks.

blossom end rot on tomatoes
Blossom end rot on tomatoes.

From your description, it sounds like your tomato plants have blossom end rot (caused by a calcium deficiency) as well as some other fungal disease on the leaves. Tomatoes are susceptible to a wide range of fungal diseases, and it is difficult to say which you have without seeing samples. You can see photos of some of the most common tomato disease in Maine at the Maine Department of Agriculture, Conservation & Forestry’s Got Pests? website. Blossom end rot can be prevented by making sure your soil is not deficient in calcium and by watering regularly. Calcium is relatively immobile and requires water to make it to your developing tomatoes.

As for your other crops (squash, pumpkins, and beans), they, too have large disease complexes. With hi-res, digital photos emailed to your local Extension office, or (ideally), physical samples sent to our plant diagnostician in Orono, we can tell you exactly which diseases you are dealing with and how to treat and prevent them.

Some best practices for preventing diseases in your garden include: choosing resistant varieties; rotating your garden plot every year, if possible; fertilizing according to soil test recommendations; mulching under all plants (plastic or straw are my favorites); and only watering at the base of plants such as with drip irrigation or soaker hoses. Reducing leaf wetness and preventing soil from splashing onto your plants is the best defense against fungal diseases.

Homemade compost can sometimes spread diseases if you put dead plants from your garden in it — a home garden-sized pile rarely will get hot enough to kill those diseases. If you are using a commercially produced compost, it should be free of diseases. Organic matter, including compost, is another good defense against diseases in your garden soil. High microbial activity can reduce viable spores. Unless you are suspicious of your compost source, I would not discontinue using it in general. Compost is not a fertilizer, though, and you will need additional amendments to maintain adequate nutrition.

Finally, there are preventative fungicides you can use in your garden. You can read more about some of your options in Pest Management Fact Sheet #5087 Early Blight of Tomato, another common disease of tomatoes.

Q: I was told long ago by an experienced farmer that one can cut broccoli in a way that will produce a second main head. I remember him telling me to cut very low on the main stalk, but now I am not certain. Do you know the method he was referring to?

broccoli in the garden

A: Some varieties of broccoli will produce secondary florets at the lower leaf axils. There is a reference to the kind of harvest you are referring to in a University of Illinois Extension publication, Watch Your Garden Grow:

The edible part of broccoli are compact clusters of unopened flower buds and the attached portion of stem. The green buds develop first in one large central head and later in several smaller side shoots. Cut the central head with 5 to 6 inches of stem, after the head is fully developed, but before it begins to loosen and separate and the individual flowers start to open (show bright yellow). Removing the central head stimulates the side shoots to develop for later pickings. These side shoots grow from the axils of the lower leaves. You usually can continue to harvest broccoli for several weeks.

Q: My tomato plants are having some ripping of the leaves. Looks like a bird may have torn them but I have seen no birds in my garden or remains of birds having been there. I spray regularly with PYOLA and the insects are under control. Any thoughts?

A: Do the leaves appear to have been eaten or just torn? If the amount of leaf tissue that is gone or damaged is limited, I also suspect birds. They are active early and late in the day, so you may not have noticed them. If that’s all it is, I wouldn’t worry too much about it. You might consider some kind of netting or row covers once you have fruit, though; if birds are looking for moisture later in the summer, they may peck at your tomatoes to get water.

Regarding the Pyola, I recommend only spraying insecticide when you know you have an insect problem, and you have identified that specific insect to confirm that it is a pest. Preventative insecticide sprays in home gardens (or anywhere) may lead to over-application and negative impacts on non-target and beneficial insects, including pollinators. Integrated Pest Management, or IPM, is a great tool for saving time, money, and the environment while getting good control of pests and diseases at the same time. To learn more about IPM, check out What is IPM? on our website.

Q: I have two grapevines about three years old. One vine is Concord. I was so excited to see tons of baby bunches of grapes about a week ago. Now I see something has been eating every single bunch. I do know the Japanese beetle, but I’ve only seen a couple so far this year and only a couple of leaves are damaged. What might be eating the baby grapes, and what can I do? I really don’t want to use chemicals since I have an organic garden close by.

Rose ChaferA: It’s hard to say what is eating your grapes without a photo. There have been many rose chafers out this year, which would happily munch on your grapes. Birds or mammals are also possibilities. As soon as you begin to see fruit develop, you can protect your plants with floating row covers, a spun-bonded fabric that lets water and light through but keeps insects and birds out. If you suspect birds and not insects, you could use netting instead. Choosing the best method of protection requires knowing exactly what is attacking your grapes. I recommend observing your grapes at all times of the day and into the evening to try and figure out which pest you need to deter.

Q: How do I get a soil sample box and form?

A: Your local UMaine Extension county office has them for pick-up on weekdays, 8:00 am – 4:30 pm. If you do not live near an office, they may mail one to you. You can also request one directly from the Soil Testing Lab.

Q: How do I make my maple tree fuller? Can I cut some off the top?

sugar maple
Image source: Paul Wray, Iowa State University,

A: Pruning of maple trees should be done when the tree is dormant (January-March). If your tree is young (10 years or less), you may be able to alter its shape with careful pruning now. Iowa State’s Forestry Extension has a great fact sheet called Pruning Young Landscape Trees that will give you some of the basic techniques. Simply topping your maple tree will not lead to a fuller (or natural) shape. It will permanently damage the tree and possibly kill it. If your tree is not young, I recommend contacting a licensed arborist to help manage your tree and meet your goals. Something else to consider, the early warm days we had this spring (followed by cooler ones) triggered a stress reaction in many mature maples. We are seeing reduced leafing and greatly increased seed production. Once the seed all drops, your tree may put out a second flush of leaves. It should look more “normal” by next season.

bee in roseQ: I recently bought a house that has a line of Rosa rugosa and possibly Rosa multiflora plants along the property line. They have not been pruned or maintained in any way for at least 1.5 years. They are currently about 4 feet tall and starting to droop over. Can I prune them back into more manageable bushes? And if so when should I do it and how much can I cut off at a time?

A: Neither Rosa rugosa nor Rosa multiflora is native to Maine, and while rugosa is not necessarily considered invasive here, multiflora is. I recommend Bulletin #2509, Multiflora Rose, Rambler Rose to learn more about this plant. This plant should be removed as soon as it is seen. If you intend to keep the rugosa, pruning should be done in early spring (March), when necessary. Remove dead and diseased canes and head back those that are over-growing their boundaries. They can withstand a fairly aggressive pruning, but will not require it each year.

Sassafras albidum tree
Photo by Chris Evans, Illinois Wildlife Action Plan,

Q: Is sassafras a Maine native plant and is it good for wildlife? I’m trying to convert my lot into more of a wildlife sanctuary.

A: The sassafrass tree (Sassafras albidum) has a wide range in the US and is native to southern Maine, though it is rare to find it in the wild. It’s leaves and twigs are eaten by many species including white tailed deer and swallowtail caterpillars. The University of Florida Extension has a fact sheet about sassafrass with more details. You may also find this publication useful as you think about designing your yard: Bulletin #2500, Gardening to Conserve Maine’s Native Landscape: Plants to Use and Plants to Avoid.

Q: Are strawberries self-pollinating? Can I use row covers during flowering?

strawberriesA: While cultivated varieties are self-pollinating, strawberries produce the best crop when bees and other pollinator species work the flowers. I recommend removing the row covers during pollination.

Q: I have covered my brassica plants — broccoli, cabbage, and cauliflower — in an effort to prevent cabbage worms. Is there a time when I can safely remove the row cover after the “season” of the cabbage moth? My garden is in Hampden.

A: In Maine, we have three different species of cabbage “worms”: Cabbage Looper (Trichoplusia ni), Diamond Back Moth (Plutella xylostella), and Imported Cabbageworm (Pieris rapae). Because there are multiple generations each season, there is never really a safe time to stop preventing your cole crops from becoming infested with one of these species. If the row covers are effective for you, I recommend leaving them on until harvest. Plenty of sunlight and water can get through to your plants, and leaving them on means you don’t have to worry about hand-picking caterpillars or applying an insecticide.

Q: Can you tell me why my dwarf Damson Plum trees aren’t flowering and bearing? This is their third season in my garden. The first year they bore a few plums. The second year, nothing. This third year they have not blossomed. I did prune them last fall.

The cross-section of a healthy flower bud shows green tissue in the center.
The cross-section of a healthy flower bud shows green tissue in the center.

A: There are a number of reasons your plums may not set fruit. It is common for plums and peaches to set fruit every other year, especially following a heavy fruit set. Have you checked the flower buds to see if they were winter-killed? In Growing Fruit Trees in Maine — Lack of Fruitfulness you can find photos of healthy and injured flower buds. Are there significant diseases (brown rot, black knot, scab) or insect pests that may be hindering overall vigor of the trees? If your trees are unsprayed, the chances of diseases or insects causing injury is much higher. Another consideration is location — do your trees have full sun? Or, are they in a place that experiences extreme cold in winter? Trees can survive lower temperatures than fruit buds can. When your trees were just planted, they had set fruit buds before you got them. There may be something about their current location that is causing them not to set fruit now.

Q: I would like directions on how to graft apple trees and hydrangea bushes.

A: A great resource for grafting apple trees that I recommend is MOFGA’s Spring Grafting Primer. I have never grafted hydrangea, but the process is the same for all woody plants.

Q: I have old blueberry plants, early to late bearing. They have never been taken care of. I was wondering if I could cut out the deadwood now. If not, when is the best time?

A: For the basics of blueberry pruning, I recommend David’s Handley’s video How to Prune Blueberry Bushes (YouTube video). It sounds like your bushes will need some more intensive pruning than what David illustrates for annual maintenance. Marvin Pritts from Cornell University addresses the rejuvenation of old blueberry bushes in a fact sheet entitled Blueberry Pruning and Rejuvenation (PDF). Here is the section that addresses your situation:

When rejuvenating an old planting, remove one or two old canes for every five or six younger canes. In following years, remove up to 20% of the wood until new cane growth occurs. Keep only 2 or 3 new canes and continue to remove up to 20% of the oldest canes. Eventually, the bush will become more productive, cane numbers will decrease, and bush stature will decline.

In old, poorly maintained plantings, some growers have had success cutting all the canes to ground level; harvesting begins 3 years later. However, for this system to be most effective, canes must be thinned to the most vigorous 6 – 10. Others find that summer hedging immediately after harvest, coupled with selective dormant cane removal, works well.

I generally prefer pruning when plants are dormant, ideally in March once the snow has melted enough that you can access the entire plant. Anything that is clearly dead now should be safe to remove whenever you like.

Q: Please advise a cover crop for my small vegetable garden, which I will not be planting with veggies this year. I’m in mid-coast Maine, ten miles from Penobscot Bay. I had clover and veggies last year. Have just tilled the clover and added compost. Possibly turned soil too deep (6 inches). I feel the soil needs a rest and nutrients. What do you recommend? Is buckwheat a good idea? What might be better?

Crimson clover
Crimson clover. Image courtesy of Wendy VanDyk Evans,

A: I recommend choosing a cover crop based on your goals for soil improvement. Do you have weed problems you would like to manage? Are you trying to increase your organic matter? Or, are you just hoping to prevent erosion while giving your garden a rest? I like buckwheat in certain situations, but it requires much more oversight than most cover crops. It is crucial to mow and/or incorporate buckwheat before it can flower, go to seed, and become your new worst weed problem. A fact sheet by Extension Specialist Lois Stack entitled Cover Crops for Home Gardens (PDF) includes a handy chart to help you choose a cover crop species. An article from the August 2014 issue of the Maine Home Garden News, Cover Crops for the Home Gardener by Extension Educator Rick Kersbergen, explores some individual species to consider as well.

Q: I have a small strip of (it used to be) grassy lawn between the main street and sidewalk in front of my home (it’s approximately 3′ wide by 30′ long at a 45-degree slope). These past two winters, it has taken a beating with the sanding and chemical road treatments and is now spotty grass in a sandy rocky mess despite hard raking each spring. Is there any ground cover that can sustain the sand and road treatments and recover each spring without replanting? It is too costly and challenging to grow grass, plus my mower is taking a beating!

juniperA: This is a very challenging environment for any plant to live in, but if this is a full-sun location, you might consider one of the low-growing junipers. Several varieties of shore juniper (J. conferta) are salt-tolerant and will be very low-maintenance once established.

Q: We are building a 10 x 20 greenhouse in Milbridge. The framework is pressure treated wood with PVC bows. The framework is finished and I’m waiting for the greenhouse plastic to arrive. My question is about the greenhouse plastic. When we put the plastic on, should the plastic on the 20-foot-long sides be permanently attached to the bottom of the wall? We would leave the ends so they could roll up for ventilation. Or should we allow the 20-foot-long sides to roll up as well? I’m inclined to permanently attach the sides. My husband wants to allow the sides to roll up. Given our climate along the coast, what do you recommend?

A: It depends a bit on what you are growing, but I always prefer the option to roll up the sides for good ventilation and/or to allow pollinators in. If you construct it that way you’ll always have the option, but if you attach them, you may regret it on a particularly hot day.

Q: I was sent some safflower seeds as a gift. Will they grow in Maine?

A: Safflower does best in warmer and drier climates than ours, but when grown as an ornamental (and not an oil crop), it is possible to get flowers late in the season. It is bordering on too late in the year to start seeds, as our season is so short. Most safflower varieties require 110-140 frost-free days, which we do not have. If you want to give them a try this year, I recommend starting seeds indoors to push growth quickly. When you transplant them, remember that they form a long taproot and will require deep soil, but not much water.

Q: I have an invasion of Japanese Knotweed. I have declared war on it but would like to know the latest info on how to eradicate this menace. Also is there a special dump in Maine to get rid of any roots I’ve dug up?

A: Japanese knotweed/Mexican bamboo (Fallopia japonica or Polygonum cuspidatum) is one of our nastier invasive plants. According to Bulletin #2511, Japanese Knotweed/Mexican Bamboo, your best course of action is repeated cutting of the stems over the course of the season. For a particularly large or established population, you might consider adding in a treatment of glyphosate, painted onto the freshly cut stems. Digging up the roots can potentially make the problem worse, as this plant will readily reproduce from a small portion of rhizome or root left in the soil. Any cutting from above ground (or below ground) should be composted thoroughly. If you do not have a large or active pile, bagging them in plastic and putting them out with the regular trash should prevent the spread.

Q: I have 50 mature asparagus plants that are very productive. This year I have more than the usual number of spears with “shepherd’s crook” malformation. I am aware that this is likely caused by the asparagus beetle larva. Is it safe to use insecticides for grub control for lawns such as Grubex and Spectracide? What chemical controls would you recommend?

Asparagus beetle larvae
Asparagus beetle larvae. Photo by James Dill.

A: Common asparagus beetle larvae can cause damage to spears that resembles a shepherd’s hook. If you are noticing a few here and there, I would not recommend any pesticide application while you are harvesting. If more than 20% of the total spears have this kind of injury or have larvae on them, you may want to think about some kind of control. Handpicking the eggs and larvae from the developing spears is the safest and most effective method to prevent further injury this spring. You will need to do this throughout harvest, as the adults are continuously flying and laying eggs. If this is not practical in your garden AND you have at least 20% injury in your spears, there are several insecticides that are effective against this pest. Look for a product with the active ingredient pyrethrin, permethrin, carbaryl, or malathion that is labeled for asparagus. It is very important that you use the correct material and apply it exactly as directed on the label. This includes application rate and waiting the appropriate amount of time before resuming harvest. The two pesticides you mentioned: GrubEx, which is labeled only for white grubs in lawns (NOT ON FOOD), and Spectracide, which is a brand including many materials, are not appropriate. Remember, using a pesticide on a crop that is not listed on the label, or in any manner inconsistent with the label is against the law and may be very unsafe. Once you have allowed the ferns to grow and leaf out, you could choose to deal with the adult population during the summer or fall when you are not harvesting. This would be my strong preference. For more information, I recommend UMaine Extension’s Bulletin #2071, Growing Asparagus in Maine and Asparagus beetles in home gardens from University of Minnesota Extension.

bee on apple blossomQ: What is the best variety of crabapple tree to pollinate a Baldwin apple?

A: As noted in Growing Fruit Trees in Maine, Baldwin apples actually have sterile pollen, so you will need at least two different varieties of apple or crab apple to effectively cross-pollinate your Baldwin. Choose pollenizer varieties that bloom at the same time as your Baldwin tree(s), such as Black Oxford, Enterprise, or Ginger Gold. Most crab apple varieties will also be appropriate.

Q: I started tomato plants in early March. Now I see they are starting to flower. Because it’s too early to plant them outside, what should I be doing about the flowering? Also, how often should I fertilize garlic?

flat of tomato seedlingsA: For even the most experienced gardeners, it is easy to get carried away and start seedlings too early. I’m afraid that’s what has happened. Tomatoes should be transplanted into the garden before they get “leggy,” and certainly before they begin to flower. When seedlings flower before they have been transplanted, it is a sign that they are very stressed and are trying to reproduce before they die. You can try removing the flowers now and moving the plants into larger pots before planting them in the ground, but these plants may never be as robust as you would like. If your plants do not recover as well as you’d like in the next few weeks, I recommend purchasing some from a local farm or garden center. In the future, I recommend not starting your tomatoes until the end of April.

Bulletin #2063, Growing Hardneck Garlic in Your Maine Garden includes information about fertilizing. Garlic is a heavy feeder, so you should plan to apply 10-10-10 or a balanced organic fertilizer at planting, and then side-dress with nitrogen once or twice in the spring as the tops emerge.

Q: We’ve been successfully growing 3 rows of Nova Scotia raspberries for years. This spring I found a tremendous amount of damage. The bark was stripped high up the healthy canes. There are piles, handfuls, of stripped bark at the base of each cane. Most all the canes have been girded or severed. Will they come back or is it best to replant? What did this damage? Will the raspberries survive? How can I help the raspberries now that this has occurred? How can I protect the raspberries in the future?

A: I suggest you cut all your damaged canes down to ground level. It’s possible that the plants are not completely dead, and new shoots may emerge this summer, but you will not have fruit this year. Alternatively, you could re-plant this spring, and then be guaranteed fruit next year on your new plants.

I believe a mammal, most likely deer, caused the injury to your raspberries. Preventing deer injury is difficult, especially in long, cold winters like the one we just had. The best way to prevent this is to erect an 8-foot fence.

Q: When is the best time by the moon to plant in June for a summer garden of annuals?

full moonA: While there is a wealth of gardening lore that claims you should wait until after the full moon to plant frost-sensitive crops such as tomatoes and beans, there is no scientific evidence tying full moons to frost. Frosts are caused when the air is still, cold, and the sky is clear. Perhaps the moon is noticed on cold, clear nights, when frosts are likely, causing people to ascribe any frosts to the phase of the moon. For more info, see “Full Moon You Say? Frost You Say?” at the Maine Organic Farmers and Gardeners Association website. I generally plan to plant any frost-sensitive annuals around Memorial Day.

Q: If I send you photos of raspberries that I inherited, can you tell me what kind they are and how to prune them?

A: I’m afraid it is not possible to determine which variety of raspberry you have with a photograph. It’s going to be tough to determine which variety of raspberry you have using any method, but the best chance is when they are fruiting. If you have particularly early, or yellow fruit, we can potentially narrow it down. There is a list of varieties that do well in Maine included in Bulletin #2066, Growing Raspberries and Blackberries that includes short descriptions. I have better news on the pruning front. This video on pruning raspberries (YouTube) with Extension Vegetable and Small Fruit Specialist David Handley includes a demonstration. Pruning is ideally done before any buds break in the spring. Depending on where you are located, you may still have time.

Q: Killarney raspberriesWhat do you recommend for fertilizing a well-established raspberry bed in the spring as well as during the year? I’d prefer to use organic fertilizers if possible.

A: According to Bulletin #2066, Growing Raspberries and Blackberries by Vegetable and Small Fruit Specialist David Handley, Raspberries should be fertilized each year in the early spring (mid-April). Apply 20 pounds of 10-10-10 (or organic equivalents) per 1,000 square feet of the planting. Increase the rate to 25 pounds if a heavy mulch is being used. It is best to split the application, applying half of the recommended amount in mid-April and the second half four to six weeks later. If you prefer organic products, look for a balanced fertilizer with some % each of N-P-K and calculate how much to apply to approximate a 10-10-10 product (which is 10% by weight N-P-K). Bulletin #2287, Applying Fertilizers on Your Home Gardens can help you determine exactly how much you need for the size of your raspberry planting. If it has been a while since you fertilized, or you do not know the history of the planting, I recommend first doing a soil test to see what the soil really needs for your raspberries to be most productive.

Q: Do you have a list of deer-resistant annuals?

A: Extension Educator Donna Coffin contributed the article Deer Resistant Ornamental Plants to the Maine Home Garden News in April 2012. She has some great tips for managing deer in your landscape as well as some plants (mostly perennials) that deer to not enjoy eating. Rutgers University has a handy tool on its website that allows you to sort Landscape Plants Rated by Deer Resistance. Using this tool, here are some of the most deer-resistant annuals:

Flowers at Thuja Garden
Angel’s Trumpet (Brugmansia sp. (Datura)) and Heliotrope (Heliotropium arborescens)
  • Ageratum (Ageratum houstonianum)
  • Angel’s Trumpet (Brugmansia sp. (Datura))
  • Anise (Pimpinalla anisum)
  • Annual Vinca (Catharanthus rosea)
  • Dusty Miller (Centaurea cineraria)
  • False Chamomile (Matricaria sp.)
  • Flowering Tobacco (Nicotiana sp.)
  • Forget-Me-Not (Myosotis sylvatica)
  • Heliotrope (Heliotropium arborescens)
  • Larkspur (Consolida ambigua)
  • Poppy (Papaver sp.)
  • Pot Marigold (Calendula sp.)
  • Rosemary (Rosmarinus officinalis)
  • Snapdragon (Antirrhinum majus)
  • Snow-on-the-Mountain (Euphorbia marginata)
  • Spider Flower (Cleome sp.)
  • Strawflower (Helichrysum)
  • Sweet Alyssum (Lobularia maritima)

Q: I bought a place in Bowdoinham and moved here in 2013. There was an existing garden area here already, in which a previous owner had planted horseradish. I attempted to get rid of the horseradish by spraying with Roundup, which I did 5 times. I still have horseradish everywhere in my garden. I do not see how I can have a garden when the only thing that grows is horseradish. One suggestion has been to abandon the garden entirely. Do you have any ideas? I would rather use the same space as a garden.

horseradish plant
Horseradish plant (Armoracia rusticana). Photo by Pethan, ©2005. CC-BY-SA 3.0 (GFDL)

A: As you have found, horseradish is a very persistent, perennial plant. Once it is established, it is very difficult to get rid of it as it propagates readily from even a small portion of the root or stems. I generally do not recommend the use of herbicides in the home garden or landscape, and 5 applications in just a few years is a lot. If you’d like to use the same area for your vegetable garden, you will likely need to commit to hand-removal of the horseradish plants. Ideally, this would be done in the fall, after a frost or two. Although, this time of year could work as well. If the soil is loose, but not wet, the roots should come up fairly easily. If the soil is too wet, or already compacted, this will be a challenge. I do not recommend rototilling, as this will spread the plant throughout the garden even further. Another option would be to solarize the soil by placing clear plastic (with no holes) over the entire garden and sealing the edges all around. This method will use the heat from the sun to kill weeds (and everything else) in the soil. It can take anywhere from 4-12 weeks for this method to work, so you may have to forgo planting it to vegetables for this season. For more information on this method, see Bulletin #2752, Extending the Gardening Season. If it’s the location you like, and not necessarily the soil, you could cover the entire space with heavy landscaper’s fabric or black plastic, and construct raised beds on top of it. There are pros and cons to this as well, but if this appeals to you, Bulletin #2761, Gardening in Small Spaces can help you do so successfully. And, of course, fresh horseradish is a prized ingredient to many cooks. Perhaps there is a small business growing in your garden!

Q: I live in Lewiston and have a backyard with a high water level; runoff floods my basement. To counteract this problem, I am thinking of planting trees there that like wet areas. Also, I’m thinking that trees would use lots of water so there would be less available for my “basement wading pool.” In my search I became interested in Juniperus virginiana, sometimes called Eastern Red Cedar. I want to plant trees native to Maine, but learned it isn’t included in the list of Native Maine trees. Could you explain why this tree is not on the list? Also, if I plant this tree on my property, will it do any damage? Thanks for your time and energy.

Eastern Redcedar
Photo by Paul Wray, Iowa State University,

A: Using trees to reduce water runoff is a fantastic idea. Juniperus virginiana (Eastern Red Cedar) is native only to extreme southwestern Maine. If you really like this species, there is no reason not to use it in Lewiston. It is well-adapted to poorer soils and will do well in a wet area. If you have any apple trees on the property, you might consider avoiding it since it serves as the alternate host for the fungal disease cedar apple rust. There are native trees you might consider for a wet area, many of which you can read about in Bulletin #2500, Gardening to Conserve Maine’s Native Landscape: Plants to Use and Plants to Avoid. Tree species that could work for you include Tamarack or Black Willow. Whenever you are planting a tree it is important to be mindful of location to be sure that you aren’t creating a problem when your tree matures. Some trees have aggressive root systems that may actually exacerbate your basement flooding issue down the road. You could use this as an opportunity to create a more diverse planting. There are many native, perennial shrubs and herbaceous plants that will also do well in wetter soils.

Q: I enjoyed your video on pruning a lilac tree. Would you be able to provide information on whether transplanting the shoots from a lilac would produce a new tree? I live in Millinocket. Thank you for any information you may have.

A: Yes, in fact, rooting cuttings is the preferred method of propagating lilacs. Penn State has great, step-by-step instructions online called Lilac Propagation by Cuttings that can help get you started. It is important to note that you will need to root your cuttings in sterile media and grow them in a greenhouse, or similar environment, as you would when starting your seedlings.

Q: I’m wondering if you offer a landscaping template with native plant recommendations for yards that are naturally wet or soggy (we live near the bottom of a hill). We have a low area in the middle of our yard that floods during rain and remains pretty soggy year-round. We would like to plant water-loving plants here, but I’m not sure if I should plant a rain garden or wetland loving plants. Any advice you can offer is appreciated!

joe-pye weedA: We do not have a template, per se, but there are some recommendations for plants that work in specific environments included in Bulletin #2500, Gardening to Conserve Maine’s Native Landscape: Plants to Use and Plants to Avoid. Species such as Tamarack, Black Willow, Bog Rosemary, Blueflag and Redosier dogwood are all appropriate choices in wet areas. Once you decide which species you’d like to plant, Bulletin #2502, Native Plants: A Maine Source List can help you find a vendor for the plants you choose. If you would like to see if a rain garden might be a good fit, check out Bulletin #2702, Landscapes for Maine: Adding a Rain Garden to Your Landscape. And, you may also like Bulletin #2701, Designing Your Landscape for Maine, which can help you plot your design before you shop for plants! Good luck with your project!

Q: I read on your (wonderful) website that it isn’t wise to plant a vegetable garden over a septic field. Is it okay to plant in 18″ high raised beds — two that are 4′ x 8′ and don’t cover a larger area. The septic field is the sunniest and flattest part of the yard. I thought I had the perfect garden spot until I read your article. But it didn’t address small raised beds over the location in question, just a garden at ground level. Thanks for your response!

A: Excellent question. I get this one often because the leach field is often the flattest and sunniest part of the yard (not to mention, the greenest). Unfortunately, I do not recommend putting raised beds on your leach field. In order to function properly, your leach field should only be planted to grass and should be mowed often to facilitate transpiration. Bulletin #2442, Vegetable Gardens and Septic Fields Don’t Mix offers a useful summary of how your leach field works and some best practices for food safety and good maintenance of your septic system. You might consider narrower beds on either side of the driveway, or working your vegetable raised beds into your landscaping. If full sun locations are hard to come by, you could consider scaling-back a bit and planting in wagons that can be moved into the sun throughout the day. A few potted tomatoes and a CSA share will also yield some homegrown flavor and support a local farm!

tomato seedlingsQ: I wonder if you can recommend video resources on seedlings, start to finish. I don’t know if I am over-thinking, but as the seedlings begin to vary in size, and lose uniformity, I don’t know how to accommodate them with the heat and the light they need. Also, at what point are they to be removed from heat? This is a hard time of year to manage a consistent warmth without a heat mat and I understand they are too warm for the seedlings at some point.

A: One of the keys to maintaining uniformity is to plant only one species (and ideally, one variety) in each tray so that you can move each one around as they get taller. Planting newer seed with a high germination rate will lead to more uniform seedlings. You should also be sure your lights are able to be moved up and down so that they are never closer than 4 inches from the tops of the plants. Heating mats are generally only necessary for germination since the soil temperature requirements are higher than from growing seedlings. Light is far more important than heat for growing seedlings. UMaine Extension Bulletin #2751, Starting Seeds at Home is a great place to start, and includes a video on building your own seed stand. There is also a chart for time and temperature needed to grow vegetable transplants with information specific to some commonly grown vegetables and fruit in Maine. Be sure to follow the instructions on your seed packets or in seeds catalogs, as they contain the best information about what your specific seeds require to germinate and grow. Additional publications, videos & other resources for all kinds of gardening topics are available on our website.

Q: Are there any solutions to discourage deer from eating plants?

A: I would like to refer you to a May 2010 article in the Maine Home Garden News entitled Deer in My Garden! by Extension Educator Donna Coffin. Eight-foot deer fencing is best, but she shares other ideas you might use as well.

Q: How do you build a raspberry trellis like the one you feature in the video on How to Prune Your Raspberry Canes? It looks like metal shelf posts. How do you sink them into the ground? I love the video by the way.

A: You can use many different types of metal or wooden posts for a raspberry trellis, though metal is best. You can rent, purchase, or borrow a post driver and sink them by hand. You could also contact a local fencing company that could do this for you. Sinking them deep enough is key to keeping your fruiting canes upright when your fruit are heaviest as well as the longevity of the trellis system.

Q: After all the deep snow has melted, we discovered that our shrubs, below the snow line, have been devastated by what we think might be “moles.” Any hints on what we have to do to stop and control this problem?

A: Moles, which primarily feed on earthworms, are not the likely cause of the injury to your shrubs. Voles will strip the bark from trees and shrubs, particularly below the snowline, where they are protected from the coldest temperatures in winter. The Maine Department of Agriculture, Conservation and Forestry’s Got Pests? website has a page on voles with fact sheets on identification and how to create a less hospitable environment for them in the future. I recommend waiting until your shrubs bud out before giving up on them. They may not be as damaged as they appear now. Once it’s clear which branches are dead, you can prune them out.

Q: I have everbearing raspberries. When pruning, using the V method, how far apart should the rows be? And should the rows go east-west?

David Handley stands beside a row of properly pruned raspberriesA: Within the row, canes should be pruned down to no more than 5 canes per linear row foot. Distance between rows should be 8-12 feet apart to allow plenty of space for you to get between the rows to mow and harvest. If you can, I recommend orienting your rows so that the prevailing winds flow down the rows to promote drying of the foliage. For more information on all aspects of growing raspberries, please see UMaine Extension Bulletin #2066, Growing Raspberries and Blackberries.

Q: I am moving into a home with a protected marshland behind it in Cape Elizabeth and want to turn the lawn into a small farm. Other than the standard soil test (pH, nutrients, lead), is there any recommended testing? Knowing that the well-manicured lawn had chemical applications, are there any recommended precautions?

Master Gardener Volunteer working in vegetable gardenA: I recommend speaking with the Cumberland County Soil and Water Conservation District as well as the Natural Resource Conservation Service office in Scarborough. They may be able to visit the property and tell you how far your setbacks are from the marshland for putting up buildings or having livestock. A lead scan is part of every basic soil test, but if you can, you should also speak with the previous owner about what was done on the property. If the soil is less than ideal, you can still create raised beds. If you are new to farming, I recommend the UMaine Extension New Farmers website, as well at the Beginning Farmer Resource Network, both of which contain a lot of information and resources for people just starting out or transitioning their farm.

Q: Is there a list of trees/shrubs no more than 25′ tall, which can tolerate windy conditions up to Zone 5? If there is such a list, how might I get a copy?

A: I recommend looking at species that are appropriate to use as windbreaks. Many of our native evergreens fit this description, although most grow taller than 25′. There is a list of recommended species in Bulletin #2500, Gardening to Conserve Maine’s Native Landscape: Plants to Use and Plants to Avoid, which includes plant height and comments on the locations where they do well. No matter which species you decide to use, Bulletin #2366, Selecting, Planting, and Caring for Trees and Shrubs in the Maine Landscape can help you get started with some best practices. Your local nursery is also a great source of information.

Q: Maple sap buckets on trees.I have been tapping a maple tree in my backyard just for the sap water. After learning all of the benefits of sap water, I would now like to share some as I have an abundance. What would be the best way to safely process and bottle? And what would the shelf life be?

A: There is new research to support that maple sap does contain many beneficial nutrients. Untreated sap has a very short shelf-life and cannot be sold “as is.” If you are interested in developing a commercial product, we have many resources for you at UMaine Extension. I recommend Bulletin #3101, Recipe to Market: How to Start a Specialty Food Business in Maine as a first step to seeing the kinds of regulations and agencies you will need to work with if you decide to move forward. There is contact information included for specific faculty whom you may wish to contact regarding food safety and product development. This publication is geared towards development of a food product. The systems for development of medicinal products are similar, but not exactly the same. You may also wish to contact Extension Educator Kathy Hopkins in Somerset County, who works most closely with the maple industry. Her email address is

Q: When and how should I prune my peach tree? I live in Lincolnville, Maine.

A: You are just in time for peach pruning! Unlike apples and other, more hardy fruit trees, peaches should be pruned in April. The trees should not have bloomed yet, but the weather should no longer be regularly below freezing. Pruning peaches (as well as plum and cherries) is also a bit different from apples. Rather than the scaffold style/shape, you are looking for more of an open vase shape to ensure good light penetration throughout the tree. For much more information on pruning peaches, as well as other aspects if peach culture, I recommend Bulletin #2068, Growing Peaches in Maine. You can see photos of peach of various ages after pruning and find links to other resources as well.

free range chickensQ: My daughter has a small flock of laying hens. I would like to use hen house waste in my garden, or around my shrubs. Can you advise me of the dos and don’ts? The garden patch is a raised bed, 30×30. The area in Winslow where we live is all ledge, so all material had to be trucked in. We have a mixture of compost mix, bought from a local supplier, sand, wood ash, and some peat moss.

A: Certain animal manures, including that from hens, are a great way to increase soil organic matter and add nutrients to the soil in our gardens. I recommend thoroughly composting your hen manure and bedding before applying it to your garden beds, or if you would like to add it directly, do so in the fall before your planting year. Check out Bulletin #2510, Guidelines for Using Manure on Vegetable Gardens for more details. If you decide to compost your hen bedding and other organic materials, Bulletin #1159, How Compost Happens can help you get started. A soil test can help you manage the mineral nutrition in your soil as well.

Q: I would like to know if you can tell me and provide literature/documentation on whether it is safe to use PVC pipes for self irrigation systems, for planting in? (I have heard many people say no, and then people say that is what our city water is piped in with. Also, to do deep water culture (hydroponics) from what I have read #2 plastic is the safest. However I also read that #1 plastic is used for store-bought water bottles and #5 plastic is used for margarine containers, yogurt containers. Most of the plastic totes/tubs on the market are #5 plastic. Can you share with me the information that you have on PVC pipes and plastic totes and buckets for gardening, self irrigation systems, and deep water culture as far as health safety? Will there be any leaching of chemicals to the water? If so is this something that the plants/vegetables?

A: It is true that most water is moved in and out of our homes in PVC (for cold water) or CPVC (for hot water) pipes. It is also commonly used for irrigation systems where freezing is not a risk. Prior to 1977, the PVC used in construction was not manufactured to the same standard as today. Now, both of these materials meet American National Standards Institute (ANSI) safety standards. According to the FDA, BPA may be leached from #3 or #7 plastics when damaged or exposed to extreme heat. These containers (generally, water bottles) are not meant to be used more than once. There is a lot of conflicting information on the internet regarding the safety of plastics. I encourage you to seek out only research-based sources when determining which materials you choose to irrigate, grow, and store your vegetables in. The Maine Drinking Water Program and the Food and Drug Administration are your best sources of information about the safety of plastics in food production.

Q: I watched David Handley’s video on pruning raspberries. Thank you; it was very helpful! What do I need to do differently, if anything, for blackberries?

A: The concepts are similar for all brambles. You want to remove all canes that have fruited the previous season, any weak or diseased canes, and thin the remaining canes down to the best. Here is a quote from Bulletin #2066, Growing Raspberries and Blackberries, written by David Handley:

Blackberries should have the growing tips of the new canes pinched off when they reach four feet. This encourages the canes to form side branches, or laterals, which will bear the fruit in the following year. Remove all canes that fruited following harvest. In the early spring, thin the remaining canes, leaving only five to seven of the sturdiest per hill. Cut the side branches back to 12 buds (usually about 12 inches in length) and tie the canes to the wire or post for support.

I hope this helps!

Q: Do you have a good choice of flowers, ornamental grasses, and herbs that are suited to plant on sunny to a partially shaded septic field in the Down East coastal region near Ellsworth? It is about 60- x 40-foot, mound-system septic field. Currently, it is the only lawn I have in my property, but I really would like to get rid of lawn altogether. It is covered with thin topsoil, but mostly sand underneath. I don’t want to plant something that would damage the septic system underground, but if at all possible, I would like to avoid using a lawnmower altogether. Also, I would like to know if it is OK to grow vegetables over the septic field? I found some source say “NO” and others say “OK.”

grassy septic fieldA: I am frequently asked this question since the leach field is often the sunniest and greenest section of a home lawn. I understand the desire to put away the lawnmower for good, but I’m afraid there are no good alternatives here. I recommend that only grass be planted on a leach field and that it be mowed regularly to promote transpiration of the grass, which helps wick moisture up through the soil. Roots of most other plants may potentially damage the system, and there is a food safety concern when growing vegetables, fruits or herbs on a leach field. For more information, please see UMaine Extension Bulletin #7080, Your Septic System, Bulletin #2442, Vegetable Gardens and Septic Fields Don’t Mix, and the Maine Department of Agriculture, Forestry and Conservation’s Vegetables — Establishment of Vegetable Gardens on Septic System Disposal Fields for more information on how septic systems work and the importance of not planting anything but grass on leach fields.

Asiatic Bittersweet choking a tree
Asiatic Bittersweet (photo by John A. Lynch, courtesy of the New England Wild Flower Society)

Q: What should be my plan of attack for bittersweet vine? It is a huge mess of vines that is growing up my trees, which I know the vine will eventually kill. How do I get rid of bittersweet?

A: Asiatic bittersweet (Celastrus orbiculata) is one of the nastier invasive species that we deal with in Maine. Is is very aggressive, as you have experienced, and difficult to eradicate from a landscape. If you are committed to removing this plant, it will likely take several years. A combination of hand-pulling young plants and cutting the stems of older vines are key. Painting a systemic herbicide (triclopyr or glyphosate) onto the cut stems of vines you cannot pull from the ground will kill the parts of the plant that are below the soil surface. For more information, please see UMaine Extension Bulletin #2506, Asiatic Bittersweet from our Maine Invasive Plants series.

Q: I have a lot of (wild) blueberry bushes and am thinking about using the wood to make a walking cane for myself. I like the way the wood curves, but is it strong enough?

A: Blueberry wood often is not greater than two inches in diameter, even on the oldest of bushes. It has a “pithy” center that may be hollow in older wood. I do not have experience using blueberry wood for walking canes. If you decide to give it a try, I recommend testing it thoroughly before using it to bear any weight.

Q: We live on a mostly wooded lot with some lawn in Waterville, ME. The soil appears to be mostly clay. We’d love to have a small vegetable garden, and have thought about raised beds. Sun shines on one part of the yard for about 4 to 6 hours a day in summer, then goes over the very tall trees. Any hope? Should we go with raised beds? If so, how deep and what type of soil?

A: squirrel in treeLiving on a mostly wooded lot (like I do) means shade in the summer, enjoying wildlife closer to your home, and less time spent mowing the lawn. Unfortunately, it also means vegetable gardening is very difficult, if not impossible. Regardless of soil quality, vegetables need full sun: at least 6-8 hours a day. For those of us living under trees, that means buying a share at local CSA or regularly visiting the farm stand to get fresh vegetables in the summer. If you were to remove some trees to get more sun, I would recommend building raised beds on your clay soil. The depth of the soil depends on whether you want to grow root vegetables, but generally, an 8-10″ deep raised bed will do. If you are very committed to having some homegrown tomatoes, you could try planting a few in containers and move them with a wheelbarrow each afternoon to keep them in the sun for at least 6 hours. For more tips on getting started in vegetable gardening, check out our extensive resources online.

Q: My neighbor planted cherry trees; he said the deer have rubbed the bark off them. What can he do/get to repair bark?

A: 3 deer in fieldDeer can do a lot of damage to landscape trees in a short period of time, especially late in winter (with a deep snowpack) when they are struggling to find enough food. The bark of a tree protects the tissue just underneath (phloem) that carries nutrients generated in the leaves during photosynthesis down to the rest of the tree. Unfortunately, unless the injury is limited to around 20% or less of the circumference of the tree trunk, there is little hope that the tree will survive. Trees with less damage may be able to heal themselves but will be more susceptible to diseases and insect pests at the injury site until it heals over. We do not recommend taking any steps to promote healing the bark, other than preventing further damage. You may find materials at the garden center meant to cover a wound on a tree trunk, but they can actually slow the healing process and create an environment where disease is more likely to be a problem. If the trunks of the trees have a diameter of greater than 2 inches, an emergency technique, know as bridge grafting can be successful in repairing the damage. For more information about bridge grafting, I recommend UConn Extension’s “Trees: Bridge Grafting and Inarching”. The best thing to do is also the hardest: excluding deer from high-value trees with 6-8 foot fencing to prevent the damage from happening.

Q: I am looking for raspberries that will produce all summer for planting in Brunswick, Maine. What do you recommend?

A: There are many varieties of brambles that do well here in Maine. For a longer harvest season, you will want to choose an ever-bearing or primo-cane fruiting variety. Varieties recommended by UMaine Extension’s small fruit specialist, David Handley, include those listed below.

For more information, we recommend Bulletin #2172, Raspberry and Blackberry Varieties for Maine.

Red raspberries, everbearing (primocane-fruiting)

  • Amity: From Oregon. Fall (primocane) crop ripens early in midseason for everbearing types. Moderately vigorous canes with spreading habit, very few spines. Some resistance to cane diseases and root rots. Fruit are medium-sized, firm, with good color and mild flavor.
  • Autumn Bliss: From East Malling, England. Early-ripening primocane crop (late August, about two weeks earlier than ‘Heritage’). Moderately vigorous canes with few spines. Productive. Fruit is large and highly flavorful.
  • Autumn Britten: From East Malling, England. Early-ripening primocane crop, slightly later than ‘Autumn Bliss’ and with more vigorous canes. Productive. Fruit is firm and flavorful.
  • Caroline: From Maryland. Mid- to late-ripening fall crop, may be too late for northern Maine. Tall, vigorous plants, with medium to large good-flavored fruit. Productive.
  • Fall Red: From New Hampshire. Early-ripening primocane crop. The medium to short canes are vigorous and produce many suckers. Moderately spiny. Fruit size is medium. Good flavor, but soft. Recommended for most sites in Maine.
  • Heritage: From New York. Primocane crop ripens relatively late, too late for all but southern Maine. Tall, rugged canes with prominent thorns. Very high yielding. Fruit size is medium, with good color, flavor, and firmness. This variety is not recommended for regions with a short growing season (frost before September 30 or cool summer temperatures).
  • Jaclyn: From Maryland. Early-ripening fall crop. Vigorous canes produce long, dark red fruit, which may be difficult to pick. Flavor is good.
  • Joan J: From England. Early ripening (about the same as ‘Autumn Bliss’). Vigorous, thornless canes produce large, somewhat dark red fruit with good firmness and quality.
  • Polana: Very early-ripening, vigorous, short, productive canes. Attractive small to medium-sized fruit, but many misshapen and difficult to pick. Flavor only fair. Recommended for northern areas with short growing seasons.
  • Redwing: From Minnesota. Primocane crop ripens earlier than ‘Heritage’ in some years and sites. Canes not vigorous, with moderate spines. Moderately productive with large fruit size. Flavor is fair to good, but fruits tend to be soft.

Yellow raspberries, everbearing (primocane-fruiting)

  • Anne: From Maryland. Fall crop ripens slightly before ‘Heritage,’ and may be too late for northern regions. Canes are tall and moderately vigorous. Fruit are pale yellow, large, with very good flavor.
  • Fall Gold: From New Hampshire. Primocane crop ripens relatively early. Canes are hardy and very vigorous, producing many suckers. Fruit is medium-sized, yellow with a pink blush, soft, but with excellent flavor.
  • Kiwigold: From New Zealand. Derived from ‘Heritage.’ Slightly earlier than ‘Heritage;’ may be too late for northern regions. Vigorous canes, thorny, fairly tall, and productive. Fruit are yellow with a dark orange to pink blush, and good flavor.

Q: I plan to start a new asparagus bed this year. Would a single row in a 3′ X 60′ raised bed with crowns planted every 2 feet allow enough room?

Asparagus spears poking up in the garden
Photo by David Handley

A: You may actually plant your new asparagus crowns a bit tighter at 12″ apart. I recommend taking a look at Extension Bulletin #2071, Growing Asparagus in Maine for more information on how to best prepare the soil for planting.

If you have not yet purchased your crowns, you may wish to consider our fundraiser, Grow It Right! where you may purchase several perennial crop plants for your home garden. Along with competitively priced, high-quality plants, you will receive educational materials. Proceeds benefit the Master Gardener Volunteers program.

Best of luck with your asparagus bed!

Questions and answers from past seasons.