By Donald Lewis
Iowa State University Extension
Butterflies and flower gardens seem to naturally go together. What better scene can you imagine than a colorful profusion of flower blossoms on a warm, sunny day and butterflies filling the air? Okay. I’ll admit that dream doesn’t come true very often, but something close to it can happen in your backyard with a little luck and a lot of planning and planting.
Creating a garden or landscape that will attract and maintain butterflies takes some special planning and effort. “Butterfly gardening” is flower gardening that gives special consideration to the needs and requirements of butterflies. Meeting their needs by providing continuous bloom of nectar-producing flowers throughout the summer increases your chances of being able to watch the adults fly from flower to flower in the privacy and comfort of your own back yard.
For the more intrepid enthusiast, butterfly gardening creates an opportunity to watch the miracle of metamorphosis – the transformation of eggs to leaf-eating caterpillars to suspended chrysalides (plural of chrysalis) and ultimately to the beautiful adults.
Raising butterflies from caterpillars in your garden often requires a major change of attitude. Caterpillars have chewing mouthparts and they must eat plant foliage as their food source. Hungry caterpillars can consume a surprisingly large amount of foliage, and butterfly gardening requires that you stand back while “worms” are eating your plants. Such tolerance is not for everyone. The initial reaction of many gardeners is to call any caterpillar a “pest” and eliminate it as soon as possible!
Caterpillars feed on foliage of trees, shrubs, flowers, vegetables and weeds. Some kinds of caterpillars are picky eaters that will eat only one kind of plant. The well-known monarch butterfly, for example, only grows where milkweeds are available. Other caterpillars can survive and grow on any of several different host plants. For example, the caterpillar of the attractive tiger swallowtail can be found on the foliage of cherry, ash, birch, cottonwood, willow or lilac.
A butterfly garden can be as small as a window box or as large as a field. However, specific characteristics about the site will improve your chances of success. First, the garden must be in a sunny location. Butterflies are predominately active in warm, bright, sunny situations and most of the plants used in butterfly gardens grow best in full sun. An exposed, windy location will discourage butterflies so provide a windbreak such as a hedge, fence or other structure to encourage butterflies to linger and help keep the taller plants from breaking over in strong wind.
Though butterflies obtain moisture from nectar, they still benefit from an available drink of water. A simple way to provide water is to put a flat porous rock in the birdbath water so butterflies have a landing and resting site.
Finally, butterflies and caterpillars are easily killed or repelled by most garden insecticides. Protect butterflies and their caterpillars by using only low toxicity insecticides such as insecticidal soap or horticultural oil only when necessary and spot-treat only those plants where insecticides are needed.
Want to know more? Raising butterflies in your garden requires learning about the food preferences of the different species of butterflies common in your area. Iowa State University Extension pamphlet RG 603 Iowa Butterfly and Caterpillar Food Preferences lists common butterflies and the plants used by the adults for nectar sources and the caterpillars for food. The pamphlet can be downloaded and printed from our Web site at www.extension.iastate.edu/Publications/RG603.pdf or visit your local Iowa State University Extension county office.