Bee-friendly tips for Minnesota home gardeners

After our seemingly endless winter, most of us are itching to load up on plants and get our hands dirty. Whether you grow on a grand scale or tend a couple of pots, chances are you'll be buying plants at a garden center or plant sale. When you do, a growing chorus of voices is urging you to keep bees in mind.

Bee die-offs, colony collapse disorder and possible causes have made headlines. They've also "made the public aware of our stewardship role with bees," said Vera Krischik, associate professor of entomology at the University of Minnesota.

In fact, bee-friendly gardening was named a top national trend for 2014 by the Garden Media Group, and Minnesota, in particular, has become a hive of bee-related activity and advocacy.

"Here in Minnesota, there's a lot going on with bees," said Lex Horan, local organizer for the Pesticide Action Network North America, which helped organize a "swarm" at a local Home Depot in February to urge the retailer to stop selling products believed to be toxic to bees.

People have been packing auditoriums for bee seminars, pushing for new legislation to protect bees and beekeepers and urging retailers to stop selling and using neonicotinoids, a widely used class of insecticides that some suspect is playing a role in recent bee die-offs.

Research on neonicotinoids' impact on bees is currently underway. But in the meantime, several large local players, including retailers Bachman's and Gertens and wholesale grower Bailey Nurseries, have decided to err on the side of caution and eliminate or sharply reduce their use of neonicotinoids.

Trying not to kill bees is only one piece of the pollinator-protection puzzle, however.

With more and more habitat lost to development and agriculture (corn and soybeans, the state's top crops, don't provide nectar), bees need food, too. And that's where home gardeners can really help, according to experts.

"The main thing is to plant more flowering plants," said Heather Holm, of Minnetonka, a landscape designer and author of the new book "Pollinators of Native Plants: Attract, Observe and Identify Pollinators and Beneficial Insects With Native Plants" (available at www.pollinatorsnativeplants.com).

Native bees, in particular, have a short flight distance — about 500 yards, she said. "If you and your neighbors aren't providing forage, they will have a hard time finding food."

From the pollinators' perspective, it's important to have a continuous succession of plants flowering throughout the growing season, Holm said. "In most gardens there is a gap," especially in early spring and late fall. Holm advises gardeners to evaluate their landscape, identify the flower gaps and fill them. Good early-spring bloomers are woodland plants, such as bloodroot, Dutchman's breeches and wild geranium. Good fall bloomers include asters and goldenrod.

And all flowering plants aren't equal, from the bee's perspective. "Stick with straight species" rather than cultivars, Holm advised. "If breeding has changed the flower color, it can also change the fragrance or nectar. It may look better to us, but it may not be attractive to bees."

When choosing plants, opt for older, simpler varieties, Holm said, even if it means passing up the plants that catch your eye with their showy form or unusual hue. "Rethink how a bee or pollinator would see your garden — not just what you think is prettiest, with double flowers or a brand-new introduction in a cool color," she said.

Good plants for bees include coneflowers, liatris, salvia, catmint, catnip, hyssop, black-eyed Susans and single-flower sunflowers, Krischik said. (For an extensive list, by region, of bee-friendly plants, visit the Xerces Society's website, (www.xerces.org/wp-content/uploads/2014/03/GreatLakesPlantList_web.pdf)

Many of the plants sold today "have been hybridized to the point that they don't have much value to pollinators," said Ron Bowen, president of Prairie Restorations (www.prairieresto.com) of Princeton, Minn., who encourages homeowners to convert 25 percent of their land to native prairie plants.

"If you plant natives, you're going to be helping something, native bees or other beneficial insects," he said. "Most of us have been taught that insects are bad, like mosquitoes. But insects are pretty important. That awakening is upon us."

To help gardeners create more bee-friendly landscapes, Bowen has developed a series of prairie-restoration kits, which contain plants and seedlings to cover a 500-square-foot area — about the size of a very large living room — along with a book about wildflowers. One of Bowen's kits, the "Pollinator Package," consists of 32 species of wildflowers and grasses that provide habitat and food sources for bees and other pollinators.

Of course, buying plants that attract bees may not be beneficial if the plants themselves are laced with toxic chemicals. A study released last summer by Friends of the Earth-US and co-authored by the Pesticide Research Institute, found that seven of 13 samples of garden plants at some large national retailers in Minneapolis, Washington, D.C., and the San Francisco Bay area contained neonicotinoids, including plants marketed as "bee-friendly." That's why bee advocates urge gardeners to make informed decisions when buying plants.

"Ask first, before you buy, to confirm they're not using systemic insecticides," said Holm. "Look at smaller, local growers rather than those who buy from others. Do your homework." The insecticides are so widely used that avoiding them can be a challenge, particularly when buying trees and shrubs, which have a longer growth cycle before they're brought to market.

"These insecticides are everywhere; they're so effective, and so safe for humans," said Jean-Marc Versolato, production manager of plant health, for Bailey Nurseries. Nonetheless, the wholesale grower recently discontinued spraying foliage with neonicotinoids, although it is still using small amounts of the systemic insecticides in granular form on some tree crops in the field. "Insects can really affect the growth of trees when they're small," he said.

Home gardeners who use insecticides are encouraged to avoid neonicotinoids, especially if they're growing plants that are attractive to bees. "If people want to use perennial natives or heirlooms, they should not use systemic insecticides," Krischik said. "They're completely legal, but they're absorbed by the plant and can end up in the pollen or nectar."

One local group, Pollinator Revival, has been working with local hardware stores and garden centers, urging them to remove neonicotinoid insecticides from their shelves. "We've made quite a lot of progress," said co-founder Julia Vanatta of Minneapolis. "Our goal is to educate consumers and retailers, get stores to voluntarily remove these products and help retailers with disposal, which is a huge cost. We can't wait until laws happen. We have to be proactive."

In the meantime, consumers should read labels and the list of active ingredients when buying insecticides, Vanatta advises. "The brand names change constantly." (If the active ingredients include imidocloprid, clothandin, thamethoxan, acetamiprid or dinotefuran, the insecticide is considered a neonicotinoid and a potential threat to bees. While active ingredients must be labeled under law, inert ingredients are not always listed, but lumped under "other ingredients"; some of these are also believed to be detrimental to pollinators.

That's one reason insecticides should be used sparingly and as a last resort, according to some bee advocates. "People have a tendency to put things on plants to prevent problems, rather than wait to treat problems once they occur," said Vanatta. "We need to be a little less fussy."

Consumers who are concerned about bees should be prepared to accept some imperfections, such as a few aphids on a plant they purchase, agreed Versolato. "Picture-perfect will be difficult without neonicotinoids."

Kim Palmer • 612-673-4784