Bees are in trouble. All bees, not just the European honeybee that is suffering from colony collapse disorder but also the native bees, of which there are 250 species in Maine, including the bumblebee.

“In Maine, there used to be 12 species of bumblebee that were quite common,” said Frank Drummond, a biology professor at the University of Maine specializing in insects. “There are at least two of those species that we know of that are if not extinct, at least uncommon.”

He said the rusty patched bumblebee and golden banded bumblebee are just about extinct in southern Maine, and rare in northern Maine.

Drummond and his UMaine colleagues Lois Berg Stack and Alison Dibble are doing a five-year study financed by the U.S. Department of Agriculture on bees and what pollen- and nectar-bearing plants support them. Bees are important to agriculture because without bees for pollination, many crops — including blueberries and apples that are important to Maine — will have lower production.

As part of the study, the professors are distributing a pamphlet to garden centers urging them to plant bee gardens designed to encourage home- owners to plant bee-friendly plants in their gardens.

Drummond listed a wide variety of native and non-native plants that support bees, and his list was supplemented by Phil Gaven, co-owner of The Honey Exchange, a bee-keeping supply and honey store on Stevens Avenue in Portland.

“The things that we try to think about as apiarists is that anything that blooms really early is great,” Gaven said, “as is anything that goes really late.”

He mentioned crocus and scilla as two early bulb plants that provide a lot of food for bees just at the time in late spring that the bees’ food supplies are running low.

Drummond mentioned willows and maples as two trees that have early-blooming flowers that bees love.

“Maples have a very teeny flower that people don’t even notice, but they are a very important provider of high-energy food for bees,” Drummond said. Gaven said that on March 16, when I interviewed him, the silver maples were already in bloom at his South Portland home, and that if the temperatures would warm up enough for the bees to fly, that would be a great food source for them.

While Drummond agreed that early and late plants are important, he said that a good bee garden should have nectar- and pollen-producing flowers all year long.

Another important plant to bees — both native and the European honeybee — is the dandelion.

“Dandelion is a weed that many people hate,” Drummond said, “but it is a crop that was brought over here in the 1620s to provide food for the honeybee. It has a flower that continues all through the year, but primarily in late April and early May.”

Gaven agreed.

“As a beekeeper, you know that if a colony can survive until the dandelions come out, they are going to thrive,” Gaven said. They are that important to the bees.

Gaven said plants that many gardeners consider evil invasives, like Japanese knotweed, are great for the bees. Both Drummond and Gaven praised clover.

Native plants that Drummond listed as being good for bees, in addition to willows and maples, are blueberries, shadbush or amelanchier, and cherries, followed by raspberries and blackberries in late June, with wild roses and similar plants in July, followed by such late plants as milkweed, clethra, aster and goldenrod.

The ornamental plants, in addition to the early bulb plants, that are good for bees include apples and cherries, roses, marigolds and snapdragons.

“Some of the ornamental plants that have been bred to have very large or double flowers tend not to be very attractive to bees,” Drummond said. “The actual flower sections that produce pollen and nectar have been bred out of them.”

I asked Drummond about bee balm, which he had not mentioned but because of its name I thought would be good for bees. It turns out that bee balm, with the scientific name Monarda, was misnamed.

“Bee balm is not a good bee plant,” he said. “It is good for hummingbirds, and butterflies are attracted to it, and they also are good pollinators, but not for bees.”

Drummond said there are many different theories about why native bees are in trouble.

One is because of climate change. Bumblebees like a cool climate, and the temperatures have been warming. Also, bees do not thrive well in forests, and the percentage of forests in the state has been growing as farms are abandoned.

Also, he said, a type of insecticide called neonicotinoids could be killing off the bees.

Another theory is that the native bees are suffering from the same pathogens that cause colony collapse disorder in honeybees.

He said none of the theories have been proven, as yet, but research is continuing.

In addition to having the right plants, homeowners can help bees by floating wood in a birdbath to give bees a landing platform and providing bee habitat. 

For information about bees, go to umaine.edu/blueberries/factsheets/bees and click on any one of the fact sheets listed. For information about the Maine study, email lois.stack@maine.edu. To contact The Honey Exchange, call 773-9333 or visit thehoneyexchange.com.

Tom Atwell has been writing the Maine Gardener column since 2004. He is a freelance writer gardening in Cape Elizabeth and can be contacted at 767-2297 or at:

tomatwell@me.com