Butterfly gardening

A sunny panorama of colourful flowers animated by a variety of dancing butterflies is an attainable dream for most Canadians. And it doesn't matter if you live downtown, in the suburbs, or in the country.

One of the most satisfying ways to watch butterflies is in your own backyard. You have a sense of creating a thing of beauty while helping to conserve a part of our natural heritage. To lift an appropriate phrase from a popular movie, Field of Dreams - "If you build it, they will come." Even the choice of the movie title would be appropriate for a butterfly garden.

There are four key requirements to entice and keep butterflies in your garden: nectar sources, larval foodplants, sunshine, and shelter. Many of the flowers already in your garden are probably appropriate to attract adult butterflies. It's a question of careful planning to ensure a variety of flower choices depending on the size and kind of the butterfly you might attract and by having flowering plants that cover all the flight seasons from late spring to early fall. Some of the more common flowering plants in gardens, such as phlox, asters, coneflowers, and lilacs are popular choices for wandering butterflies to visit; these can be grown in any part of Canada. Some other plants are a magnet for butterflies, but can only be grown in the more southerly parts of the country. These include Buddleia (Buddleia davidii), also called Butterfly Bush, and Butterfly-weed (Asclepias tuberosa), an orange-flowered member of the milkweed family. With the proper sunny and sheltered exposure these can be maintained for many years. There are also a number of Canadian wild flowering plants that, if they can be accommodated in your garden, will certainly be an asset to attracting butterflies. Highly recommended are Joe-Pye-Weed (Eupatorium maculatum), Black-eyed Susan (Rudbeckia hirta), and species of thistles (Cirsium spp.).

The important point is that these flowers are all high in nectar content. If you want to attract butterflies, hybrid garden plants with almost no nectar, such as roses, lilies, and geraniums, are of little use.

Equally important to attracting and keeping butterflies in your garden is the planting of larval foodplants. Female butterflies will sometimes wander large distances looking for these foodplants and if you have them available they are a guaranteed attractant. Sometimes local colonies can be established for butterflies that do not wander far from the larval foodplants.

Your backyard vegetable patch can draw in some females. Planting any member of the mustard family will entice members of the white butterflies (pierids), and in particular the Cabbage White (Pieris rapae). Growing carrots or, even better, carrot relatives, such as parsnips and dill, will likely bring in the Black Swallowtail (Papilio polyxenes) in eastern Canada and the Anise Swallowtail (P. zelicaon) in the west. If having a maximum yield on your vegetables is your goal, this could pose a problem. You may wish to grow a little extra to ensure enough for yourself and for the butterflies.

Most butterflies are quite choosy in their larval foodplants, some keeping to a single species of plant, or to a genus or family of plants. You should become familiar with the more common local butterflies before you determine what plants to put in your garden. For instance, if sulphurs are in your neighbourhood, then having alfalfa or clovers on your property for their caterpillars would be a good idea.

Some weedy plant species are a must for keeping certain butterflies about. Monarchs must have milkweeds for their larvae (and, as a bonus, most other species nectar on milkweeds) and many of the brushfooted butterflies, such as the Painted Lady and Red Admiral (Vanessa spp.) and anglewings (Polygonia spp.), require thistles or nettles. These can be placed at the back of the garden, out of sight (and touch) of human visitors. The butterflies will find them.

Certain trees, in particular willows, oaks, aspens and cherries, are used as food by the larvae of many lycaenid butterflies, such as hairstreaks (Satyrium spp.) and azures (Celastrina spp.) and some brush-footed butterflies (Nymphalis and Limenitis spp.). Again, become familiar with the more likely butterflies to be found in your area and then refer to the Early Stages sections of the species accounts in this book.

Butterflies are basically creatures of sunshine. For most, you must have enough sunlit areas in your garden to keep them about. This may be difficult in some small city gardens, and some pruning of shrubs and trees may be required. However, if you are close to a woodland, there are some shade-loving butterflies, such as the satyrs, that will only be present if there is some shade available. Shelter from the wind is another essential for a good butterfly garden. There are few butterflies that will tolerate a high wind for very long, especially while they are nectaring or searching for larval foodplants on which to lay their eggs. Trees and shrubs that act as foodplants and nectar sources serve a further purpose as protection from the wind.

Finally, there are specific artificial enhancements to your backyard that will help to draw in butterflies and keep them there on a regular basis. Some butterflies like to 'mudpuddle,' that is, to gather at nutrient- or salt-enriched wet patches on the ground. You can recreate this by keeping a patch or box of sand dampened. Some butterflies only feed as adults on substances such as rotting fruit or decaying flesh. Any old oranges or grapefruits opened up will attract some of these butterflies.

For the anglewing butterflies, including commas and the Question Mark (Polygonia spp.), tortoiseshells, and the Mourning Cloak (Nymphalis spp.), there must be an overwintering site for the adult available. They often use hollow logs or the eaves of houses and garages. You can install a hibernaculum (an overwintering box that looks like a large bird box with an opening at the bottom or slits along the side) to offer them shelter during the winter months. However, areas frequented by any of these species usually have abundant natural overwintering sites.

Butterfly gardening has become a very popular activity in many parts of the world, including Canada. There are several good books available to give more detailed advice. The best on the market is Butterfly Gardening: Creating Summer Magic in Your Garden by the Xerces Society. Remember that this text covers all of North America and some of the plants recommended are unsuitable for Canadian gardens.

Reproduced with permission from The Butterflies of Canada by Ross A. Layberry, Peter W. Hall, and J. Donald Lafontaine. University of Toronto Press; 1998. Specimen photos courtesy of John T. Fowler.