The ideal butterfly garden is in full sun and sheltered from the wind. Sun is important because butterflies need to warm up after cooler overnight temperatures. You don’t see them on the wing much before mid-morning when the sun is stronger.
Stones are useful in the garden because they absorb the sun’s heat and provide basking spots where a butterfly can “charge up its battery.”
Making a garden
Most people do not have ideal sites. However, just choose the sunniest spot in your yard, put in good nectar plants, and the butterflies will come. All the plants listed below are quite easy to grow and do not require special conditions. Although Joe-Pye Weed and Swamp Milkweed prefer moist soil, they will grow in dryer conditions as well.
Violets are among the earliest nectar plants to flower, followed by arabis, forget-me-nots, chives, sweet rocket, and dianthus. Then come the summer yarrows, daisies, mallows, milkweeds, coneflowers, and rudbeckias. Finally, Joe-Pye Weed, goldenrods, and asters.
Besides good nectar plants, butterflies need special host or larval plants on which to lay eggs. After the eggs hatch, the caterpillar or larva spends its life eating the leaves of the host plant. As it grows bigger, it sheds its outer skin four to six times before becoming a chrysalis. Finally the adult butterfly emerges and the cycle may be repeated, depending on the species and time of year. On average, from egg to adult takes about a month.
Not any plant will do for caterpillars. Each butterfly species has its preferred host plants. Female butterflies search for these particular species on which to lay their eggs. You can often see one flying from plant to plant, landing briefly on a leaf, then taking off again. The butterfly is “tasting” the leaf through sensors on her feet to see if she has found the right one.