Maine Home Garden News — March 2017

March Is the Month to . . .

By Tori Jackson, Extension Educator: Agriculture and Natural Resources, UMaine Extension Androscoggin & Sagadahoc Counties

  • Prepare your indoor garden for increasing daylight by repotting any root bound plants, taking cuttings to propagate new plants, and fertilizing ahead of increased growth and bloom.
  • Sterilize pots, trays, and tools you will use for seed starting. Remnants from last season’s plants and even dust from the shed or barn can transmit disease. Seedlings require a sterile environment to get the start they need to produce all summer long.
  • Attend Maine’s Garden and Flower Shows to get ideas for your yard and garden this year.
    • BDN Garden Show at the Cross Center in Bangor March 24-26, 2017.
  • Learn more about Cooperative Extension’s Maine Harvest for Hunger program. Maine again ranks third in the nation in food insecurity. Farmers, Master Gardener Volunteers and home gardeners all have a role to play in helping to address this issue. Grow food for your neighbors, area seniors and food pantries or join a gleaning team to gather thousands of pounds of food for donation from participating farms. This is an important time of year to contact the individual or organization where you plan to donate to find out what produce is most needed.
  • Plan your vegetable garden. Use graph paper or (my favorite) spreadsheet software to create a scale map of your vegetable garden to help you decide how many seeds or seedlings you will need and how much garden hose or drip tape it will take to keep things watered. See our Planting Chart for the Home Vegetable Garden for the earliest and latest safe dates to plant in Maine.
  • Ask the UMaine Extension gardening experts! If you have a question about something you are seeing in your own garden or how to prepare for the upcoming growing season, browse the archive first and then ask your own question here.
  • Prune your perennial fruits and woody landscape plants. When the snow has begun to melt but everything is still dormant, it can be a great relief to get back outdoors to manage your yard and garden. Prune out weak, diseased, or superfluous canes and branches to improve airflow and increase yields of healthy fruits.
  • Complete your 2016 Master Gardener Volunteer Training. If you missed any classes during your training last season, work with your county MGV coordinator to make up sessions at a nearby 2017 class.
  • Prepare to mitigate drought. Following the drought of 2016, farmers and gardeners should plan now for a potential lack rainfall in the upcoming season. A new resource has been developed for farmers that contains information gardeners can use as well. Read Resources to Navigate Drought Successfully to learn more.
  • Consider Beekeeping. With concerns about the decreasing populations of pollinators around the world, gardeners are learning how to keep their own bees. Find a nearby Bee School on our events calendar.

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Gardening for Biodiversity

By Marjorie Peronto, Extension Educator, UMaine Extension Hancock County

We live in the sixth mass extinction period of Earth’s history, a period of unprecedented plant and animal species loss. Conservation biologists tell us that overall extinction rates are now 1,000 times higher than the historical rate of one to five species per year, with future extinction rates likely to be 10,000 times higher. Habitat loss is the number one cause of Earth’s biodiversity crisis.

We gardeners can play an important role in reversing the current trend in biodiversity loss. Studies show that public and private gardens represent a growing percentage of suitable habitat for many threatened species. Gardening for biodiversity means selecting and nurturing functional plants in our garden: those that provide shelter, food, and breeding ground for many forms of life, including insects, birds, small mammals, reptiles, and amphibians.

We had some serious epiphanies in our garden when we took the time to put our tools down and quietly observe. Most of them had to do with insects, which shouldn’t be surprising, since insects comprise 60 percent of Earth’s biodiversity. While often overlooked, or sometimes cursed, insects deserve to be recognized as the lynchpin of the garden ecosystem. Everyone knows we need the pollinators. We need the predatory insects and the plant eating insects (“insect herbivores”), too, the creatures who, if nurtured, will coexist in a delicately linked web of life.

Monarch butterfly on Asclepias incarnata
Monarch butterfly on Asclepias incarnata, our native swamp milkweed. Photo by Reeser Manley.

Among our garden epiphanies was the diversity of life that we encountered one summer in a small patch of swamp milkweed (Asclepias incarnata). We planted the milkweed to attract monarch butterflies with hopes that they would lay eggs on the milkweed leaves.

In early August we spotted two adult monarchs, and two weeks later we discovered 20 small caterpillars munching on the leaves. Two more weeks and the larvae were full grown and ready to pupate. By early September there were new adults nectaring on a variety of garden plants.

Milkweed aphids on Asclepias incarnata.
Milkweed aphids on Asclepias incarnata. Photo by Reeser Manley.

Soon after the monarch caterpillars pupated, the plants in our milkweed patch were nurturing hundreds of tussock moth caterpillars and thousands of milkweed aphids. It was astounding how quickly these creatures appeared. The tussock moth caterpillars ate the remaining milkweed leaves while the aphids sucked sap from the stems and seed pods.

ladybird beetle larvae hunting aphids on Asclepias incarnata
Ladybird beetle larvae hunting aphids on Asclepias incarnata. Photo by Reeser Manley.

As the population of aphids reached “standing room only,” we were delighted to find the first ladybird beetle larvae preying on them. Before long there were several ladybird beetle larvae, each eating about 400 aphids before pupating. By the end of summer, the feeding of all these life forms reduced our milkweed plants to naked sooty-mold covered-stems. And thus the cycle was complete. The following year vigorous new shoots emerged from the underground crowns, ready to begin the cycle anew.

predatory wasp carries a caterpillar
A predatory wasp carries a caterpillar back to its nest to feed its young. Photo by Reeser Manley.

I suspect that you, like Reeser and I, enjoy the multitude of birds that visit our gardens. Did you know that each pair of chickadees requires between 6,000 and 10,000 caterpillars to raise a single clutch of fledglings? This is the case for 96% of North American songbirds. Caterpillars are what bird food looks like. Other garden animals that depend on insect herbivores include amphibians, reptiles, rodents, and small mammals, as well as spiders, harvestmen, and the larvae of predatory and parasitoid wasps.

holes chewed in oak leaves
Normal caterpillar munching does not reduce the vigor of a tree, and is a sign of healthy garden biodiversity. Photo by Reeser Manley.

Tree leaves that are riddled with holes in September by the chewing of caterpillars and other herbivores should not be cause for alarm; they are a sign of a functional garden.

The following is a short list of easy to find functional garden plants that enhance garden biodiversity.


  • Clethra alnifolia (Summersweet)
  • Cornus alternifolia (Pagoda Dogwood)
  • Hamamelis virginiana (Witch Hazel)
  • Ilex verticillata (Winterberry Holly)
  • Morella pensylvanica (Northern Bayberry)
  • Sambucus canadensus (American Black Elderberry)
  • Vaccinium corymbosum (High Bush Blueberry)

Herbaceous Perennials:

  • Asclepias incarnata (Swamp Milkweed)
  • Astilbe x arendsii (Astilbe)
  • Echinacea purpurea (Purple Coneflower)
  • Echinops ritro (Globe Thistle)
  • Lysimachia clethroides (Gooseneck Loosestrife)
  • Monarda fistulosa (Bee Balm)
  • Nepeta x faassenii (Catmint)
  • Solidago spp. (Goldenrods)
  • Symphyotrichum novae-angliae (New England Aster)

More information on gardening for biodiversity can be found in The Life in Your Garden: Gardening for Biodiversity by Reeser Manley and Marjorie Peronto (Tilbury House Publishers, Thomaston, ME, 2016.)

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Staff Picks: Acer species

By Kathy Hopkins, Extension Educator, UMaine Extension Somerset County

red maple leaves
Red Maple (Acer rubrum)

Many of my favorite plants any time of year are members of the Acer genus, more commonly known as maple trees. They produce the first agricultural crop of the season, maple syrup, usually beginning in February or March. They are one of the first to bloom, coloring the woods with a delicate tracing of red or yellow in late spring. In the summer, they provide luxurious shade from the hot summer sun providing a blessing for plants and animals. In the fall, they provide a last explosion of color before the pristine whiteness of winter descends on Maine.

There are about a dozen species of maple trees native to North America and one species that can grow as far south as Guatemala. World-wide, there are also species of Acer native to Korea, Japan, and Europe. European native Acer platanoides (Norway maple) is considered an invasive species in Maine.

Maples generally grow as trees although some, like Mountain maple or Acer spicatum have a shrub form. Most have palmately lobed leaves with veins that radiate out from the petiole although boxelder, also called Ashleaf maple, Acer negundo, has compound leaves. All Acer species have opposite leaves making them easy to spot when out on a walk.

Red maple samaras
Red maple samaras

Maple seeds or samaras develop from the flower clusters or chains. Samaras are usually joined in pairs, each having a membranous wing that can carry the seed on the wind out and away from the parent tree to find a patch of less competitive fertile ground in which to sprout. Each species has a uniquely shaped samara. A good identification book can aid in classifying the different maples by their seeds.

Maine has five native Acer species: Red (also called soft, white or swamp) maple Acer rubrum; Sugar (also called rock or hard) maple, Acer saccharum; Silver maple, Acer saccharinum; Striped maple Acer pensylvanicum; Mountain maple, Acer spicatum.  Maine has two non-native maple species that have naturalized in the state: Boxelder, Acer negundo and Norway maple, Acer platanoides. Both species are sometimes considered invasive. Norway maple and its cultivars such as ‘Crimson King,’ ‘Columnare’ and ‘Schwedleri’ are now listed on Maine’s newest Invasive Plant list. These will be illegal to import, buy, sell or propagate after December 31, 2017.

Maple trees in northern North America produce sap that can be boiled into syrup in late winter and early spring. Sap flow begins when nights are below freezing and the days warm to about 45 degrees Fahrenheit. This temperature change causes a positive pressure in the sapwood of the tree. In the warmth during the day, activity in the cells produces carbon dioxide that is released into spaces between the cells. The carbohydrates produced by photosynthesis the previous summer are stored in the tree in the form of starch. Starch is converted to sucrose (sugar) and dissolves in sap in the spring. Amino acids dissolved in the sap give a characteristic maple flavor, which differs from white or brown sugar and other sweeteners. These components dissolved in sap also add to the osmotic pressure within the tree, causing sap flow in the spring.

Spring is also a great time to get out and visit a sugarhouse on Maine Maple Sunday™ or visit one of the many maple festivals across the maple producing region of North America. Even British Columbia, while it has no sugar maples, has a “Bigleaf Maple Syrup Festival” to celebrate its small but tasty syrup production.

For more information on identifying maples, go to the Maine Forest Service Forest Trees of Maine

For more information on Maine Maple Sunday™ and sugarhouses open to the public, go to

For more information on invasive plants, go to Invasive Plants.

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“Plant a Pollinator Garden!” Kicks Off at Maine Flower Show

By Kate Garland, Horticultural Professional, UMaine Extension Penobscot County

If you attend the Maine Flower Show this year, you will have a chance to pick up a FREE pollinator seed packet and take part in the Million Pollinator Garden Challenge. That’s because the Maine Landscape and Nursery Association (MELNA) was just awarded a grant from the Maine Department of Agriculture to provide seed packets for attendees of our inaugural Maine Flower Show. The seeds will be a mystery until you visit our website and unlock the code to find out which pollinator-friendly plants your packet contains, along with directions to grow and care for them. Each packet will also have instructions on how to register your planting as one of the gardens in the Million Pollinator Garden Challenge.

The National Pollinator Garden Network tells us that:

Pollinators are responsible for 1 out of 3 bites of food we take each day, and yet pollinators are at a critical point in their own survival. Many reasons contribute to their recent decline. We know for certain, however, that more nectar and pollen sources provided by more flowering plants and trees will help improve their health and numbers. Increasing the number of pollinator-friendly gardens and landscapes will help revive the health of bees, butterflies, birds, bats and other pollinators across the country.

MELNA and Plant Something Maine are proud to support this effort to create pollinator-friendly gardens across the state of Maine, and very excited to launch our first Plant a Pollinator Garden! at this year’s Maine Flower Show. Tickets are now on sale; buy them here on Eventbrite.

Special thanks to Gary Fish for the beautiful photos in the slideshow below.

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Food & Nutrition: Sprout Safety

By Kathy Savoie, MS, RD, Extension Educator, UMaine Extension Cumberland County

With the arrival of spring, some gardeners like to get sprouting early with bean and seeds sprouted at home. Like any fresh produce that is consumed raw or lightly cooked, sprouts may contain bacteria that can cause foodborne illness. Sprouts are often served on salads, wraps, sandwiches, and Asian foods. Unlike other fresh produce, sprouts from seeds and beans need warm and humid conditions to sprout and grow. The warm and humid conditions are also ideal for the growth of bacteria, including Salmonella, Listeria, and E. coli.

If just a few harmful bacteria are present in or on the seed, the bacteria can grow to high levels during sprouting. Home-grown sprouts also present a health risk if they are eaten raw or lightly cooked.

What you can do to reduce your risk of illness:

  • Children, older adults, pregnant women, and persons with weakened immune systems should avoid eating raw or lightly cooked sprouts of any kind (including onion, alfalfa, clover, radish, and mung bean sprouts).
  • Wash sprouts thoroughly under running water before eating or cooking. Washing may reduce bacteria that may be present, but it will not eliminate it.
  • Cook sprouts thoroughly to reduce the risk of illness. Cooking kills the harmful bacteria.
  • When you’re eating out, ask that raw sprouts not be added to your food. If you buy ready-made sandwich, salad, or Asian food, check to make sure raw sprouts have not been added.

Read this publication to learn how to treat seeds first in order to reduce risk when growing your own sprouts.

Adapted from Produce: Selecting and Serving It Safely, U.S. Food and Drug Administration, April 2016

Additional UMaine Extension resources on food safety with fruits and vegetables

Master Food Preserver Volunteer Program

Are you interested in becoming a Master Food Preserver Volunteer through an extensive hands-on food preservation training? You will learn the art and science of food preservation and develop expertise in food safety, canning, drying, freezing, fermenting, and winter storage. Master Food Preservers become familiar with materials and equipment in home canning, identify and avoid food safety problems and successfully preserve products. Master Food Preservers serve as volunteers and resources in the community to provide the public with research-based information from the University of Maine Cooperative Extension and USDA. Send an e- mail to: or call 1.800.287.1471 to be placed on an interest list. Applications will become available in April. For more information visit Master Food Preservers.

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University of Maine Cooperative Extension’s Maine Home Garden News is designed to equip home gardeners with practical, timely information.

Let us know if you would like to be notified when new issues are posted. To receive e-mail notifications fill out our online form.

For more information or questions, contact Kate Garland at or 1.800.287.1485 (in Maine).

Visit our Archives to see past issues.

Maine Home Garden News was created in response to a continued increase in requests for information on gardening and includes timely and seasonal tips, as well as research-based articles on all aspects of gardening. Articles are written by UMaine Extension specialists, educators, and horticulture professionals, as well as Master Gardener Volunteers from around Maine, with Katherine Garland, UMaine Extension Horticulturalist in Penobscot County, serving as editor.

Information in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of products or services mentioned. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.

© 2017

Call 800.287.0274 (in Maine), or 207.581.3188, for information on publications and program offerings from University of Maine Cooperative Extension, or visit