The butterfly effect

Gardening for these jewel-like pollinators is about more than just flowers

by  Moira Farr

When I bought a home in Cobourg (a little more than an hour’s drive east of Toronto, on Lake Ontario) two years ago, I inherited a garden that had been lovingly tended by a gifted gardener. As a novice, I have been intimidated, but also delighted and determined to learn whatever I can to carry on the previous gardener’s good work – especially when it comes to making my patch of land butterfly friendly. Late that first summer, I noticed a sun-drenched clump of tall, yellow-petalled flowers that were laden, day after day, with monarch butterflies. The plant, I learned, is grey-headed coneflower, a nectarrich monarch magnet (its seeds also feed birds in the fall). Black-eyed Susan, another native nectar species commonly recommended for attracting butterflies, has also lived up to its billing, with its long, accommodating petals and small florets that a butterfly can easily probe for nourishing food.

I now understand that providing a variety of enticing nectar plants (visit ontarionature.org and click on the ON Nature section for a list of butterfly-friendly flowers) in sunny, wind-sheltered spots is just one way to make your garden a truly welcoming butterfly habitat. Every butterfly species has preferred larval-host plants (see “Floral delights,” this page). Monarchs in the caterpillar stage feed only on plants in the milkweed family, for instance, while American painted lady prefers pearly everlasting. Black swallowtails are attracted to parsley, dill and carrots, and fritillaries, to violets. “You learn to love the larvae,” says Dianne Pazaratz, who spearheaded the creation of extensive butterfly gardens – one actually in the shape of a butterfly – on land owned by the City of Oshawa. The gardens contain dozens of larval-host and nectar plants, from nasturtiums (attractive to the cabbage white) to false nettle (for the red admiral) and shrubs such as spicebush (for the spice-bush swallowtail), and spirea (for the spring azure). A member of both the Durham Region Field Naturalists, an Ontario Nature member group, and the Durham chapter of Canadian Organic Growers, Pazaratz praises the low-maintenance, pesticide-free garden (the latter condition is a must for a butterfly-friendly habitat). “You grow enough for beauty and enough for food,” she says.

When providing food and shelter to caterpillars and butterflies, “diversity is key,” says Daisy Moore, an Elora-based horticulturalist. Gardeners should include flowers in a variety of colours and with flat petal shapes that make easy landing pads. “The general principle is to have something in bloom throughout the growing season.” Moore suggests hawthorn, lilac and flowering cherry as early-blooming choices. Willows are a big food source for admirals, viceroys and swallowtails; in shrub form, willows are suitable for the urban garden. “It is a myth that they need wet soil,” she says.

Moore has had great success with New England asters, which bloom in late August and early fall. “The monarchs love the nectar; it’s like chocolate,” she says. As well, the orange flowers of butterfly weed are “stunning in the garden,” she advises. Other favourites she recommends include Joe-pye weed, blazing star, coreopsis and bee balm.

Experts also suggest providing flat stones in full sun as basking spots and creating small “puddles” – even a shallow bowl of water with sand on the bottom will allow butterflies to rest and feed on the mineral salts.

With these amenities, a wide range of nectar and larval-host plants, and no pesticides, your garden should attract its share of butterflies, though the species types and numbers will probably vary from year to year. “Ringlets and crescents are consistent, but one year you’ll see lots of sulphurs or monarchs, then not many the next,” says James Kamstra of Port Perry, an environmental consultant and long-time participant in, as well as two-time organizer of, annual butterfly counts in the Durham, Oshawa and Sunderland regions. Roughly 275 species of butterfly occur regularly in Canada. Participants in last year’s Sunderland count documented sightings of 60 species, establishing a Canadian count record (and a friendly rivalry with Haliburton butterfly counters, who usually count around 50). Kamstra notes that the most common species of all is the European skipper, a non-native species that feeds on the abundance of non-native grasses such as Kentucky bluegrass and timothy, and “has probably out-competed the native skippers.” He has also seen changes in other native populations over the years: the silvery blue has expanded its range south from the Canadian shield while the wild indigo dusky-wing, a fairly rare Carolinian species, has moved from the United States north into Ontario, adapting to feed on crown vetch in the absence of its preferred food, wild indigo.

You might find the odd rarity amid the more common species of butterfly alighting in your garden, as did Ontario Nature member Margaret Carney, who was lucky enough to discover and photograph a giant swallowtail in her Whitby garden several years ago, a first record for the Durham region. She also once happily hosted a pipevine swallowtail and was so excited by the find, and admiring of its “blue satiny, gorgeous, glinty wings,” that she removed a clematis vine growing on her house and replaced it with a swallowtail-friendly pipevine. “Now if one ever shows up again, we’re ready for it.”

Rare or common, many butterfly species are in decline globally, due to climate change and the habitat loss that results from development and pesticide use. For further motivation to create a butterfly-friendly garden, Lorraine Johnson, author of several books on gardening with native species, recommends the recent book Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens, by U.S. author Douglas W. Tallamy. She agrees with his argument that native plant gardens, especially large, suburban ones, “may be our last hope for the biodiversity of insects.”

So consider your butterfly garden to be an ecological oasis and even a lifesaver. “I really think,” says Johnson, “that urban and suburban gardens can make a big difference.”
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Moira Farr is a freelance writer who divides her time between Cobourg and Ottawa. Her last story for ON Nature was about birdhouses and bird feeders (“Fly away home,” Summer 2007).