A Garden for the Rusty-Patched Bumblebee: Creating Habitat for Native Pollinators by Lorraine Johnson and Sheila Colla (2022 paperback) 250pp Douglas & McIntyre $23.00 (special $6.95 summer discount price here at ROTN!)

There’s a small pile of books on a table by my desk - the writers are my go-to references for garden questions. Heather Holm, Doug Tallamy and the late Henry Koch are my guides, and of course Lorraine Johnson, whose 100 Easy-to-Grow Native Plants has been by my side since its publication in 1999.
Now Johnson, along with co-author York University professor Sheila Colla, has produced another winner: A Garden for the Rusty-patched Bumblebee - Creating Habitat for Native Pollinators (Douglas & McIntyre) is a wonderful introduction to the world of our pollinating friends.

Like so many other insects, the Rusty-patched is a bee that was once abundant across eastern Canada and North America and is now in steep decline. In Canada, the last individual was found, by Colla, in 2009 at Pinery Provincial Park. In 2012 it had the “unfortunate distinction” of becoming the first native bee to be designated as endangered in Canada.

There could be many contributory factors such as loss of habitat, competition from non-native honeybees, pesticides and climate change. But “given the dramatic speed and geographic extent of bee loss, conservation scientists believe a new disease brought in by managed bees is the main driver of decline,” the authors write.

Bumblebees as well as some other native bees use buzz pollination, a vibration technique that makes them better than honeybees at pollinating certain types of plant, including tomatoes. I first learned about how bumblebees became an industry from Laurence Packer’s Keeping the Bees, published in 2010. He describes North America bumblebees being taken to Europe for trials where they may have picked up an Old World disease from European bumblebee being reared in the same facility.

I was horrified to read that some of these bees were returned to their native range to breed and work in greenhouses here. It’s in the nature of things that some escaped the greenhouse and it has been shown since that bee diseases are more prevalent closer to the greenhouses where industrially reared bees are being used than they are further away. Will we ever learn not to wantonly move creatures and plants around the globe, courting environmental disaster?

Well, our job as gardeners is to mitigate the disaster. We can create and extend habitat using the native plants that form vital systems of association with native pollinators.

“When we fill landscapes with introduced, non-native plants, we are severing crucial, dependent relationships between native plants and wildlife that have evolved over millennia,” the authors write. “These partnerships and interdependencies support all life on Earth, including us.”

Don’t non-native plants attract pollinators too? Yes, but it’s not necessarily a good thing. Many of the relationships between insects and flowers are highly specific and it’s the pollen from the host plant genus or species that is needed for the larvae to develop properly.

“Non-native plants may provide pollinators with some of the resources they need, such as nectar, but not the pollen or other resources (oils, for example) that specialist bees require, nor the host plants that moth and butterfly larvae require.”

The same applies to cultivars of native plants. The research data are limited but one study found that a hybrid species of Cardinal Flower provided less than 20 per cent of the nectar energy that the straight species provided.

The part of the book that will be of abiding interest to gardeners is the main section with more than 300 profiles of native plants. Each listing offers an illustration of the flower, details of blooming period, soil and exposure requirements, along with a short description. I checked to see if my favourites were there and was happy to find them. Spikenard? Yes! Field Thistle? Yes! Bladdernut? Yes! Sorry, I have too many favourites, have to stop.

I made a list as I went of “must-gets:” Yellow Pimpernel, Climbing Fumitory and Canada Milkvetch caught my eye as potential future favourites. This is the book to have at your side when going plant shopping or making up the seed list for next year. To help with planning, there are sample designs at the back of the book for different situations.

While Johnson may be Canada’s best known gardening writer, Colla is less of a public figure. In conservation science, however, she’s known for her research on bees and she's part of an active and influential group associated with the Centre for Bee Ecology, Evolution, and Conservation at York University.

Check out her recent scholarly article on ‘bee-washing,’ the apian equivalent of ‘green-washing’ (namely, the promotion of what appear to be environmentally positive practices, but are in fact cover for harm that’s being done).

One example of bee-washing: the bee hotels that people can buy for above-ground solitary bees. A study of 600 bee hotels in Toronto found that wasps were more abundant than bees in three quarters of them, and and that many of the nesting bees had been parasitized. Diligent cleaning and maintenance is required or the hotels become a vector for transmission of bee diseases and pathogens. Best to have your bee hotel in your garden’s hollow stems, dead or standing wood and the leaf litter that you leave under trees as overwintering habitat.

Some other ideas from Johnson/Colla: If you live in an apartment, they provide a list of natives that do well in containers. You can overwinter the pots by adding leaf mulch that will provide protection against the killing freeze-thaw cycle. You could also start a pollinator patch by pitching the idea to a local school, library, faith centre, park or other public, private or corporate space. Funding can be found for pollinator gardens.

A “good news” story recently started to unfold at Pinery Provincial Park, where adults have been found following release in 2021 of 700 endangered Mottled Duskywing butterflies. This is cause for celebration as generally such re-introductions do not work in the first year. Success required years of preparation, planting the butterfly’s host plant, the New Jersey Tea, seeding native wildflowers for nectar, and control of invasive species.

The Rusty-patched bumblebee is a generalist pollinator that visits hundreds of different species of plants from April to October. What you do for it will benefit many other insects as well as birds that depend on insects for food.

So roll back that lawn and garden for the Rusty-patched!