This week Elspeth Hay learns about a simple backyard project that can help increase garden yields and attract native species of bees.
We’ve been talking recently on the Local Food Report about honeybees—why we need them, what challenges they face, and what local beekeepers, farmers, and citizens are doing to safeguard them. But native insects that act as pollinators are also part of this conversation. This week, Elspeth learns about a simple backyard project that can help increase garden yields and attract different, native species of bees.
A few years ago, Lee Ann Norgeot of Harwich noticed a funny looking drawing in the Fedco seed catalog. It was a square block of wood, maybe 6 inches on a side, with different sizes of holes drilled into the front. The caption called it a native bee nesting box:
L: As a gardener I’m always noticing different types of bees on all the plants—there’s so many different types of native pollinators, but a couple of the native species of bees that are so common around here are mason bees and leafcutter bees and they’re the kinds that will move into these nesting boxes.
Mason bees get their name from the fact that they cap the end of their nesting tubes with mud and leafcutter bees do the same thing with leaves. Unlike honeybees, these native bees live as individuals—they’re not part of a bigger colony.
L: So the native bees are looking for long tube shaped chambers in nature, so something in wood or reeds like bamboo or marsh grass, so if you provide those sites that they’re looking for they will go right to them, and you want to have plenty of flowering plants around with a wide variety of blooming times and also just a wide variety of different types of flowers.
E: When you create this habitat, what are some of the benefits from a food perspective?
L: You will get increased pollination so that will help with the quality of the fruit and vegetables, and the yield, and just the overall health of the plants.
Numerous studies have been done on why and how this works. Pollination occurs when pollen from the anther—also called the male part of the flower—moves onto the stigma, or female part, of a flower. This can happen with help from the wind, but bees and other insects are much more efficient. When compatible pollen is moved onto the stigma, the plant is fertilized and forms seeds. The more pollen gets on the stigma, the more fertilized the flower is, and the more seeds it produces—which in turn means it makes a bigger fruit. Fruits that haven’t been properly pollinated are often small and misshapen—there is a great pictures of this from a study done at the University of Minnesota below. The other exciting thing about attracting native bees for gardeners is that as pollinators, they’re extremely efficient.
L: It takes about 250 native bees to do the same amount of pollinating as it would take about 10,000 honeybees, they’re just hardier bees, so they’re flying on days when honeybees just won’t be flying, and that includes rainy days but also season extenders, they’re flying earlier in the season and later in the season.
It’s important to remember that honeybees are native to southeast Asia—and while they’re naturalized, they’re not as hardy in our climate as the true native bees. Lee Ann has her native bee nesting box mounted on her hoophouse. She says as long as there’s a nesting spot and plenty of flowers, the bees will come.
L: For me it took a couple weeks at first but pretty much around mid May maybe early June depending on the season, you will start to see some activity, little cells capped off, things that weren’t there the day before and you’ll get a pretty good variety too—leafcutter bees, Mason bees, so it’s kind of fun to watch.
Lee Ann says that because the bees don’t have a hive or colony to protect, they tend to be fairly docile, and make a good introduction to bees for kids. And they’re also safe around a shed or a house.
L: These bees actually don’t drill their own holes, so if you do attract them with these nesting boxes, you don’t have to worry about them drilling into your house, they’re totally different.
Lee Ann’s making native bee nesting boxes out of fir and cedar, because these woods weather resistant, but you can also use any kind of log in your yard or natural wood. The one thing to avoid is pressure treated wood—this could make the bees sick and isn’t somewhere you want to attract them. I’ve gotta say, I’m inspired—I’ve always wanted honeybees, but I haven’t had the time to learn. This is a simple way to attract native bees —and hopefully get more vegetables and fruit. For WCAI’s Local Food Report, I’m Elspeth Hay.
You can find a link to Elspeth's blog about food, Diary of a Locavore.
Lee Ann Norgeot's tips for attracting native pollinators to your garden:
Grow a variety of plants with a wide range of bloom times throughout the season. Avoid using chemical fertilizers, weed killers, or pest controls.
Annuals: Such as alyssum, zinnias, and sunflowers will provide plenty of foraging for different types of pollinators.
Perennials: Heaths and heathers bloom in late winter and early spring. This gives bees the ability to forage on warm days before other plants are blooming.
Herbs: Sage, lavender, and oregano can thrive in poor soil under dry conditions, making them a low maintenance and eco-friendly choice for the garden.
Wildflowers: Queen Anne's Lace, Rudbeckia, clover, and milkweed are just some of the many wildflowers that provide food and habitat for all kinds of beneficial insects and pollinators. Milkweed and butterfly weed are important food sources for monarch caterpillars.
Trees and shrubs: Clethora is a fragrant native shrub which attracts a wide variety of pollinators. Linden trees bloom in spring, and give enough space will grow into large shade trees, making them a large source of food for bees wild providing a habitat for birds.
The Local Food Report is produced by Atlantic Public Media
This piece first aired in January, 2018.