The second best way to attract butterflies to your yard is by filling your landscape with plants that butterflies feed on. The best way is to plant a combination of plants that attract butterflies and feed caterpillars. As an added bonus, the plant varieties which flying flowers and their offspring find irresistible are also favorite nectar producers for hummingbirds.
Many gardeners fear that caterpillars will destroy their plants, not true. Most butterfly species only lay one or two eggs on a host plant, then fly away to another host plant to lay another egg or two. As a result of the egg-laying habit, caterpillars do not hatch in large enough numbers in any one location to cause plant destruction.
Moth offspring are usually responsible for the destruction gardeners find, but the similar appearance causes the blame to be placed on butterfly offspring due to a case of mistaken identity.
Knowing the right vegetables, flowers and trees to plant will make you a good host for butterflies and caterpillars. For example, the common black swallowtail finds carrots, dill, parsley and fennel to be the perfect meal for their newly hatched offspring and those are favorite plant choices for their egg-laying excursions. Plant a variety of these vegetables in different locations in your garden to ensure some eggs will reach maturity and while providing the desired harvest for yourself.
Plants for Caterpillars
These plants, which are a good mix of vegetables, flowers and trees, will attract butterflies to your landscape, provide desirable host plants for the flying flowers to lay their eggs, feed caterpillars, look good in your landscape and some will attract hummingbirds and other types of winged creatures.
* Carrots, as mentioned previously, attract black swallowtails. So does dill, parsley and fennel.
* Asters attract pearl crescents
* Everlastings, which are category of small annual flowers that are easy to dry, like daisies and marigolds. These annual blooms will attract the American Lady butterfly.
* Pansies attract variegated fritillary
* Passionflower hosts gulf fritillary, variegated fritillary and zebra longwing
* False nettle attracts red admirals and eastern commas
* Snapdragons are favored by the common buckeye
* Violets, both native and cultivated, are gracious host to most fritillaries
* Milkweed is for monarchs
* Flax plays host to variegated fritillary
* Toadflax attracts common buckeye
* Cherry trees, both the black and choke cheery varieties, are favored by the tiger swallowtail* Willow trees feed caterpillars and hosts several butterfly varieties, including the viceroy, red-spotted purple, morning cloak and western tiger swallowtail.
Dept, of Development and Cell Biology, University of California, Irvine
The Butterfly Website