A butterfly house. Check garden centers and mail-order catalogs for the little wooden shelters that protect butterflies from birds and bad weather. Most come with a mounting pole, and all have narrow vertical doors that are too small for hungry birds to enter.
Showy displays of color attract butterflies. Plant flowers with blooms of vibrant purple, orange, yellow, and red. Single blooms provide better access to nectar than double blooms do. And avoid flowers that hang downward or have ruffled edges; butterflies will find them hard to sip from.
Plant in bunches. Butterflies are more likely to revisit a group than a single plant.
Overripe fruit is also attractive to butterflies. Leave dishes filled with mixes of mashed fruit, molasses, beer, or fruit juice in the yard. Or soak dish towels in the mix and drape them over trees and shrubs.
Certain plants are irresistible to butterflies. One is so attractive to the colorful little visitors that it shares their name: the butterfly bush (Buddleia davidii)—a graceful shrub with showy clumps of vibrant purple flowers. Marigolds, nasturtiums, impatiens, zinnias, hollyhocks, and daylilies are among the flowers they love, along with sweet william, heliotrope, purple coneflowers, bright red bee balm, and—not surprisingly—butterfly weed (Asclepias tuberosa). As for herbs, the most seductive are borage, dill, fennel, chives, and wild bergamot. Other good lures are wisteria, coreopsis, white clover, sweet alyssum, lantana, snakeroot, and sedum. Tailor-made seed combinations designed to attract butterflies are offered by some of the larger garden seed companies.
Remember that when you create an environment hospitable to butterflies, you’re also inviting them to lay the eggs that will become caterpillars. The cabbage white, for instance, is a destructive pest to nasturtiums, cabbages, and radishes. One solution is to plant enough for both you and the pests. Luckily, most other caterpillars are not excessively greedy. At worst, they munch a few leaves without doing much damage—a small price to pay for the beautifully colored wings they will bring into your garden.