Scott's Experimental Bee Hotel

If you’re like me, you might be considering putting a native bee condo in your garden or community orchard right now. It seems like a great way to celebrate the spring, to enhance our gardens by attracting pollinators, and to help our waning native bee communities at the same time.

And heck, bee condos are getting pretty fashionable these days. Just google “bee condo” and look at the images. You’ll see a wide array of beautiful little structures you can integrate in your garden while, all the while, knowing that if they could talk, your native bees would be thanking you.

Or would they? A Toronto based researcher has discovered recently that native bee condos help more than just native bees. In some cases, condos could be a trap for native bees. That’s because some parasitic insects see bee hotels as an all-you-can-eat buffet. And can you guess what their favorite snack is? Yup, native bees.

Indeed, nature can be quite violent. But even so, researcher Scott MacIvor discovered that native bees weren’t the only residents of the 200 number of bee hotels he set up across Toronto as part of his study with Dr Laurence Packer of York University from 2011-2013. In fact, they were the minority:

“There are a lot of different insects and animals that use dark and dry holes to make a nest, including native bees,” McIvor says. “We wanted to discover who was using these bee hotels through our study.”

At the end of the season, Scott collected these boxes and inspected the contents. What he found was surprising. Native bees were a minority in many bee hotels. This is what he discovered in his study:

  •     50% of the “bee condo” occupants were wasps
  •      25% were non-native or introduced bees
  •      25% were native bees
  •      Other occupants included spiders, birds and even a mouse!

But hey, wasps are good too, according to MacIvor. Especially if you are growing fruit trees and fruiting plants in your yard. That’s because wasps eat insect pests including aphids, caterpillars, inch worms and beetle grubs.

Close up of one of the bee condos MacIvor installed as part of his study.

Close up of one of the bee condos MacIvor installed as part of his study.

So should we put up bee hotels in our gardens? MacIvor says yes – but realize that some designs are better than others. If you want a good design, check out a respectable site like xerces.org

Or you can say no to the “beewashing” and save your money. The best way to help native bees is by being a good gardener.

Here are his suggestions:

  •      Plant a diverse range of colorful flowers for them – including perennials, native plants and of course – fruit trees!
  •      Plant raspberries or lilacs as native bees use their leaves for nesting materials.
  •      Put a dish of water in your garden for the bees and refresh it daily.
  •      Install a rock garden on a south east facing slope to attract ground nesting native bees.
  •      Be a messy gardener! Don’t clean up your garden too much before the winter as bees can nest in flower stems or use the pithy or woody stems of burning bush, sumac, elderberry or berry canes to nest in.

“We need to broaden the conversation (about native bees and how to help them),” says MacIvor.  “A good way to contribute to native bee population is to be out in nature and observe nature and find where they are nesting and leave that area alone. That’s one great way that we can encourage native bees.”

Resources:
Scott MacIvor Study: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0122126
Learn more about native bees: http://www.xerces.org/
Excellent reading on bees: Attracting Native Pollinators: The Xerces Society Guide, Protecting North America’s Bees and Butterflies by Marla Spivak

Susan Poizner is the author of the award-winning fruit tree care book Growing Urban Orchards and is the creator of the educational website OrchardPeople.com.