Creating a Butterfly Garden
A butterfly garden requires a little planning and proper selection of nectar producing plants. By choosing a variety of native plants and plants that bloom at different times, you can enjoy a diversity of butterfly species all summer long.
Start with a Native Plant Palette
Nectar producing plants are the key to butterfly gardening, because they attract adult butterflies that will seek food while they mate and lay eggs. Since insects and plants have co-evolved as interlinked communities, their association with each other has resulted in many unique physiological adaptations. However, few people realize that the plants they choose for a butterfly garden can have a profound effect on biodiversity. Non-native plants from other continents simply do not have the same food value to Virginia insects.
Doug Tallamy, an ecologist, entomologist and professor at University of Delaware, uses the following example to explain how our landscaping interferes with native insect-plant interactions: "We have planted Kousa dogwood, a species from China that supports no insect herbivores, instead of our native flowering dogwood (Cornus florida) that supports 117 species of moths and butterflies alone. In hundreds of thousands of acres we have planted golden raintree from China instead of one of our beautiful oaks and lost the chance to grow 532 species of caterpillars, all of them nutritious bird food. My research has shown that alien ornamentals support 29 times less biodiversity than do native ornamentals." [Read more about Tallamy's fascinating results at the link listed in the resource section at the end of this article.]
Therefore, we recommend choosing plants for your garden that are native to Virginia. [See the resource section for the National Plants Database, where you can look up individual plant species and see their distribution and weed status.] Unfortunately, many of the popular butterfly-attracting plants on the market today are invasive exotics that have escaped cultivation and are now taking over untended areas such as roadsides, woodlots and naturalized fields. Learn these plants!
For example, some NON-native shrubs to AVOID, because they are known to naturalize and therefore compete with native biodiversity, include butterfly bush (Buddleia spp.), glossy abelia (Abelia grandiflora), Japanese spirea (Spirea japonica) and Rose of Sharon (Hibiscus syriacus). BETTER choices for butterflies would be sassafras (Sassafras albidum), New Jersey tea (Ceanothus americanus), spicebush (Lindera benzoin), sweet pepperbush (Clethra alnifolia), Virginia sweetspire (Itea virginica) and buttonbush (Cephalanthus occidentalis).
More Nectar Producing Plants
In addition to the flowering shrubs mentioned above, numerous annuals will attract butterflies to your garden, and many can be easily grown from seed. Cosmos, marigolds, sunflowers, verbenas and zinnias are excellent seed choices. Although many of these are not native, they are not currently known to be problematic, whereas dill and fennel are invasive. Lantana is an absolute butterfly favorite—in fact, you may have to shoo the butterflies away when you go to purchase a pot of lantana from the nursery! It's considered a perennial further south but an annual in most of Virginia, although you can't grow it from seed.
To encourage continuous visitation, plant nectar flowers that bloom at different times throughout the season so that you have blooms from June through October. Flowers should also be planted in full sunlight and in large groups rather than individually. This is because butterflies, like many insects, are nearsighted. They are more likely to be attracted to a large grouping of flowers in your garden than a few single flowers.
Perennial butterfly favorites for your garden include purple coneflower (Echinacea purpurea), threadleaf coreopsis (Coreopsis verticillata), blazing star (Liatris spicata), bee balm (Monarda didyma) and black-eyed Susans (such as Rudbeckia hirta and R. fugida).
Native perennials in the milkweed genus are very important to butterflies for both nectar and reproduction, such as common milkweed (Asclepias syriaca), swamp milkweed (A. incarnata) and butterfly weed (A. tuberosa). Similarly, the phlox genus is also a good choice: thick-leaf phlox (Phlox carolina), wild blue phlox (P. divaricata), summer phlox (P. paniculata), creeping phlox (P. stolonifera) and moss phlox (P. subulata). Plants that bloom late in the season like goldenrods (Solidago canadensis and S. odora) will extend the beauty in your garden until frost.
Other beneficial natives include Joe Pyeweed (Eupatorium fistulosum), New York ironweed (Vernonia noveboracensis) and plants in the aster genus (Aster laevis and A. novae-angliae). Remember to include vines in your landscape, too, such as maypops or passionflower (Passiflora incarnata).
Another way to entice butterflies into your garden is by offering host plants. The best gardens are those which combine nectar plants and host plants together, for maximum effect. In this way you will encourage butterflies to spend more time in your garden as the females explore sites for laying eggs. Adult butterflies rely on a variety of nectar plants for food but require very specific plants for laying their eggs, because the caterpillar offspring or larvae must feed on the leaves of particular species.
Be prepared to watch caterpillars defoliate an entire host plant (another good reason to plant your beds in masses, so there will be plenty to go around). You'll see these tiny larvae grow bigger day by day as your plant disappears! If you grow herbs like parsley in the garden, plant extra to share with black swallowtail larvae. The caterpillars of some species like the monarch are "obligate," which means they're obligated to feed on only one kind of plant; in the monarch's case it's milkweed. For other butterfly species, the caterpillars use a wide variety of host plants, including trees, such as the following:
Eastern swallowtails - wild black cherry trees, willows, tulip trees, sweetbay
Painted lady caterpillars - hollyhocks, thistles, mallows, sunflowers
Anise swallowtails - anise, parsnip
Buckeye caterpillars - snapdragons, verbena and toadflax
Spicebush swallowtails - spicebush, sassafras
Pearl crescents - asters
Red and white admirals - wild cherry trees, black oaks, aspens, yellow and black birches
Other Habitat Needs
Butterflies need a damp spot for drinking water. They prefer mud puddles or wet, sandy areas. You can sink a bucket completely filled with sand into the soil and fill it with water so that the top is damp. A rock or twig in the sand will provide a perch.
Tempted to buy one of those cute butterfly boxes? Although it may look nice in your garden as a decorative feature, these boxes don't actually provide protection for butterflies. Instead, butterflies are adept at finding shelter from bad weather under leaves, eaves and brush.
Butterfly or Moth?
Butterflies and moths have many similarities and both belong to the insect order Lepidoptera. One distinction between the two is their antennae. Butterflies have antennae that are knobbed on the end, whereas moths' antennae are usually straight, branched or even feathery. A butterfly's body is usually smooth and slender, while a moth's body tends to be fuzzy and plump.
Another telltale sign is how they hold their wings. Butterflies rest with their wings upright, and moths typically rest with theirs spread out. Also, moths tend to be active at night and butterflies during the day. However, you'll want to keep an eye out for the sphinx moth on cloudy days. Often referred to as the "hummingbird moth," its large size and fast-beating wings appear to mimic a hummingbird as it probes from flower to flower.
Your Butterfly Habitat
Avoid using pesticides in or near your butterfly garden. A balanced wildlife habitat with a diversity of plants for food and cover will ensure that predators like wasps, assassin bugs and spiders will visit your garden and keep insect pests in check. Without chemicals you may have to tolerate a few pests, but you're less likely to harm the butterfly larvae you're trying to attract.
With just a little planning and effort, you will reap many months of pleasure from your butterfly garden year after year. Butterflies will naturally be attracted to you butterfly garden, so there is no need to order butterflies or eggs. Ordering butterflies for any reason requires an advance permit from the U.S. Department of Agriculture, Animal and Plant Health Inspection Service.
By simply including host plants among your nectar plants, you can witness first hand the entire butterfly life cycle. And, since butterfly numbers are decreasing due to pesticide use and land development, you and your garden will play a very important role in butterfly conservation.