Butterflies will visit, and possibly stay to lay eggs, wherever there is a variety of plants for food and shelter, some moisture, and an absence of pesticides. While there are typically more species in warm climates than in cooler ones, there are butterflies almost everywhere in the country. Their appearance in your backyard ultimately depends on whether their favorite plants are growing there - certain ones to support their larvae, many others to support adult butterflies.

Larvae (caterpillar) host plants
The typical garden is not likely to incidentally have plants that host the larvae of most butterflies. The caterpillars of each species usually favor the foliage of specific plants or plant groups at this stage of their lives. Larval host plants are often unattractive, weedy and wild, generally unpopular in cultivated gardens. Yet, adult female butterflies choose these particular plants (Monarchs must have milkweed!) to lay their eggs on. This assures that newly hatched caterpillars have appropriate food immediately at hand, or the noxious compounds from plants that repel predators.

Typically, young caterpillars begin voracious feeding immediately after hatching, virtually skeletonizing host plant foliage. Watch a parsley worm (Swallowtail) devour the foliage of Queen Anne’s Lace, carrots, or parsley. Butterfly larvae grow as they eat, shedding their skins 4 to 6 times before achieving maximum size for pupating. Only then do they desist, becoming immobile in a hard chrysalis suspended from a leaf or stem of the larval host plant until emerging as an adult butterfly.

Butterfly Host Plants
Fortunately, adult butterflies have more cosmopolitan palates. The flower nectar they need for energy is available in many different flowering plants. They will visit your yard in search of those most easily accessed by their long, coiled tongues, or proboscis, which enables them to reach deeply into the center of flowers where the glands that produce the sweet nectar are located. They are particularly attracted to hot-colored, fragrant flowers. They get further nutrition from moisture from puddles and raindrops, rotting carrion and other liquids that provide traces of minerals and nutrients not in nectar.

Butterfly Garden Design
The butterfly gardener’s challenge is to provide diversity of plants in communities throughout the property to support both larvae and adults. Variety is the key. Choose many kinds of herbs, annuals and perennials, vines, groundcovers, shrubs and trees. Assure that blooms are available to visiting butterflies for the entire season. The greater the variety of suitable plants, the greater the potential number and variety of types of butterfly visitors.

It is not necessary to integrate larval and adult plants throughout the landscape. Just allow some part of your yard or nearby property to remain weedy and undeveloped to lure female butterflies to lay eggs. Somewhere in the yard, let fresh water accumulate to support communal “mudpuddling”, so butterflies get soil salts and minerals as well as moisture. Overripe fruit that has dropped from trees also provides nutritious moisture. Finally, butterflies like some flat stones for basking, or sunbathing, to gather warmth to power their wings.

Butterflies visit flowering plants that are in full sun and in sites sheltered from wind in beds or containers. Protect garden beds exposed to the wind with a hedge of glossy abelia or butterfly bushes (Buddleia) or a wall or trellis covered with honeysuckle or passionflower. Flowering shrubs provide shelter for roosting, too. The more fragrant, the better. Plant at various heights, because like birds, certain butterfly species prefer to feed at certain heights. Some species are quite territorial and try to chase others from favorite plants.

Finally, unlike the famous monarchs which migrate to Mexico and other points south, most butterfly species overwinter nearby. This means that their eggs, chrysalises, or larvae are likely to be in or near your yard during the non-gardening months. Some will even hibernate as adults. Do not mow weedy sites and dismantle woodpiles which provide them safe shelter in the off-season.

Favorite larval host plants include asters, Bermuda grass, clover, hollyhock, lupine, mallow, marigold, milkweed, nettle/thistles, parsley, passionflower, plantain, snapdragon, sorrel, St. Augustine grass, turtlehead, and violet.

Caterpillars: Distinguishing Friend From Foe
Butterfly larvae tend to be solitary, or sparsely distributed, whereas pest caterpillars such as fall webworm make tents and hatch in the hundreds. The latter are best handled by pruning the tent out of the tree or breaking it open so that the birds can eat the immature larvae.

However, even in sparse numbers butterfly caterpillars can damage ornamentals or food plants. For example, the ubiquitous white cabbage butterfly lays eggs that turn into destructive green worms which devour cabbage and broccoli and their relatives. An insecticide product containing Bt (Bacillus thuringiensis) sprayed onto plant foliage will handle feeding worms that threaten to destroy crop yields. In the case of parsley worms on parsley, simply moving them to a non-essential plant such as wild carrot will both save the crop and preserve the eventual butterfly.

Taken in part from writings of the National Garden Bureau, Liz Ball, author