Plant A Butterfly-Friendly Garden

It was a cold and drizzly day in May as I worked in my perennial border thinning, transplanting and putting labels back where I thought they belonged. The clematis vines were emerging, and I went to encourage one up a piece of rebar when there was a buzz near my ear. I was about to reach and swat when the buzzing circled from my back and stopped, mid-air, just feet from my face. It looked at me and sped off. It was a brilliantly colored ruby-throated hummingbird.

For a number of years, I’ve had at least two of these speedsters in my garden and as the season progresses they are only outdone in ornament by the butterflies. And sure enough, the next day, with a little sun and warmth, a yellow swallowtail passed through. The hummingbirds seem to be attracted to the diversity of flowers but the butterflies are much more difficult, challenging and more subject to the vagaries of our weather. Out here in a good year, we may see up to a dozen varieties of butterflies but if you know where to look and when, the count can go well above 100.

Some, like the cabbage butterfly (which is a true butterfly and not a moth) show up early and hang around very late in the season. Others, like the monarch, grace us on their migration north and then again on their migration south. But, what all the butterflies have in common is that they are individually attracted to specific plants that they either feed on in their caterpillar stage or sip on as adults in search of nectar.

Not only is it necessary to have “food” plants in your garden that will attract butterflies as they feed on the nectar and where their offspring caterpillars can feed and pupate into flutterers, but it’s also necessary to offer places where the females will lay their eggs and where both sexes have access to water. Some females are pickier about which host plants to lay their eggs on than others. For example, caterpillars of the monarch butterfly develop only on the milkweeds while the black swallowtail feeds only on parsley, dill and closely related plants. And it’s not only the butterflies that can be noteworthy. The larvae, which we know as caterpillars, can be quite spectacular having hairs or forked spines (such as the tomato hornworm) which may or may not sting, and intriguing bands of color and spots. Certain swallowtail caterpillars imitate snakes or bird droppings. Other caterpillars like the sulphers are camouflaged and blend into their surroundings so well that they are rarely noticed. If caterpillars are eating excessive foliage (the aforementioned downside) they can simply be picked up (with gloves please) and gently moved to another less noticeable portion of the plant.

Remember that insects—and butterflies are insects—are cold-blooded and they cannot internally regulate their body temperatures. They will readily bask in the sun when it’s warm out, but few are seen early in the morning, on cloudy days or in deep shade. It’s a good idea to leave open areas in a yard for butterflies to sun themselves as well as partly shaded areas where they will tend to hide on cloudy days or cool off on oppressively warm days.

Butterflies also like puddles and they can often be seen at a pond or stream’s edge and even at the edge of a fountain that isn’t splashing. Males of several species will congregate at small rain pools after a thundershower, forming what is referred to as puddle clubs or mud clubs, where it is thought they get mineral supplements from the water as well as moisture. Permanent puddles or water features will also work but what works best is a feature that is sunken and then filled with small stones or gravel and water.

Adult butterflies have mouthparts shaped into a long, coiled tube. Forcing blood into the tube straightens it out allowing the insect to feed on liquids, its sole diet. They get all of their food through this tube, which limits them to nectar and standing water. It’s a common misconception that they also feed on pollen. And it’s only the larval stage, the caterpillars, that have the chewing mouthparts that enable them to eat foliage.

Adults have large, rounded compound eyes that allow them to see in all directions without turning their heads and each species seems to be attracted to certain colors related to the flowers they sip on. They see you coming from all sides. Like most insects, they are very nearsighted and are more attracted to large stands of a particular flower than those planted singly. This explains why I can have hundreds of butterflies on my small 4-foot-by-9-foot patch of coneflowers that becomes a riot of colors and flutters.

They do not see “red” as well as we do, but they can see polarized light, which tells them the direction the sun is pointing, as well as ultraviolet light, which is present on many flowers and guides them to nectar sources. They also have very well-developed senses of smell, which is picked up not by a nose but via their very complex antennae.

If you intend to plant specifically for the butterflies, it should be considered that many of the plants that they find most attractive are actually weeds in other settings. They are the ultimate naturalists. Good examples are thistles and dandelion—all highly attractive to several of the more common butterflies but not exactly what you want to encourage in the landscape. Also consider that a well-tended and manicured garden and lawn will actually discourage butterflies from establishing a habitat. The highest concentration of butterflies that I’ve seen is in free-form gardens where the gardener or designer has simply let loose.

Insecticides, both chemical and organic, can be a major problem. Caterpillars are highly susceptible to the natural insecticide Bt, which is used to control cabbage loopers (also a butterfly larvae), gypsy moth caterpillars and a host of other garden and plant eaters. There is also great controversy about some farm plants (most notably corn) which is available with a Bt-enhanced gene that can be deadly to passing (feeding) butterflies. As for garden insecticides, adult butterflies can be killed as they rest on a surface that has been insecticide treated.

As noted, there are about a dozen different butterflies that you can fairly easily attract to your garden. They have wonderful names like swallowtails, monarchs, red admiral, painted lady, great spangled fritillary, mourning cloak and others. You can tempt each one with a particular plant and its nectar, but it takes some research as well as patience. Here’s a partial list of annuals, perennials, trees and shrubs that will help your and their endeavor: asters, bee balm, butterfly bush, butterfly plant, Coreopsis (tickseed), cosmos, Gaillardia, goldenrod, Hibiscus (perennial), joe-pye weed, marigold, ornamental thistles, parsley, phlox, purple coneflower, sunflowers, sweet peas, verbena and zinnias.

Also remember that you need to provide food for the caterpillars, so to the above list please consider: broccoli, cabbage, carrot (or Queen Ann’s lace), willow, hackberry, cottonwood, aspen, elm and locust.

There are a number of excellent guides and keys to butterflies if you’d like to know more about what’s passing through or feeding in your garden or pausing at your puddle, and there is also a long list of books on butterfly gardening. Peterson Flash Guide to Butterflies is an easy-to-use and conveniently folded, laminated pictorial key with text.

Just remember that you can plant till you’re 100 and plant all the “right” plants, but if you’re trying to attract butterflies that don’t naturally pass our way—it just ain’t gonna happen. Keep growing.