Of all the creatures that visit our suburban garden near Chicago, butterflies are the most exotic and magical. On warm summer days they sail from one flower to another in search of nectar. In sunlight, the shimmering wings of the red-spotted purple appear iridescent. And while the large, brightly colored swallowtails and painted ladies tend to grab our attention, there are countless smaller species—colorful coppers, crescents, checkerspots, hairstreaks, skippers, metalmarks, blues and others roughly the size of a thumbnail—that are just as fascinating and fun to watch.
No matter where you live, it’s easy to invite a variety of these winged wonders into your yard. A butterfly garden is simply one that offers nectar for the adults and certain plants for their caterpillars. If you grow flowers, you likely have nectar plants that attract them. Nectar is a sugar-rich liquid that butterflies, bees and other pollinators rely on for energy.
A butterfly’s tongue is shaped like a flexible straw, which it unrolls and dips into the base of a flower. Native perennials like bee balm (Monarda), purple coneflowers (Echinacea) and black-eyed Susan (Rudbeckia) are good sources of nectar, but many butterflies are attracted to easy-to-grow annuals such as Mexican sunflower (Tithonia), zinnias, lantana, cosmos, marigolds, ageratum and verbena.
During their short lives, butterflies must find food, avoid predators, seek shelter from bad weather, find a mate and reproduce. On top of these daunting tasks, female butterflies must find suitable plants, called host plants, on which to lay their eggs.
Each species of butterfly requires specific plants for its caterpillars to eat. Monarchs, for example, will only lay eggs on milkweed (Asclepias) plants. No other plant will do. For this reason, I grow the colorful swamp milkweed (Asclepias incarnata) and butterfly weed (Asclepias tuberosa), both well-behaved perennials in my beds and borders. Like most perennials, they only bloom for a few weeks, so I also grow the annual milkweed, (Asclepias curassavica), which flowers from May through October in our zone 5 climate.
The elegant zebra swallowtail will only lay eggs on the native pawpaw tree (Asimina triloba). Some hairstreaks lay their eggs on oaks, hickories and butternut trees while the question mark butterfly lays eggs on the leaves of elm, hackberry, hop vines and nettles.
Eggs are laid either singly, in rows, or in clusters. Once the eggs hatch, the caterpillars feed almost constantly. As they quickly grow larger, they shed their skins five or six times until the full-sized caterpillar crawls off to a sheltered spot where it sheds its skin one last time. The new skin hardens to become a chrysalis (also called a pupa). What happens next is positively magical. Inside the chrysalis, the caterpillar’s tissues are liquefied and rearranged—a process called metamorphosis—as it transforms into a butterfly.
I have found chrysalises hanging from the underside of chairs, on the side of the house and on branches. Last summer, a monarch caterpillar travelled more than 50 feet from milkweed plants, made it across the lawn, a sidewalk, onto the front stoop and up the side of a pedestal and ceramic container where it attached itself to the top of a small evergreen next to our front door. The pale green chrysalis was studded with gold dots like a piece of jewelry. Before long, we could see the dark wings forming inside, and within a matter of days the butterfly emerged and was gone.
Top Photo: “Monarch Chrysalis”, Bottom Photo: (L) “Chrysalis – Wings Showing”, Bottom (R): “Monarch Caterpillar”. All Photos: Nina Koziol
Depending on the species and the season, the chrysalis stage may last a few weeks or as much as six months. When the adult butterfly is fully formed, the chrysalis skin splits and the butterfly emerges, hanging on to the shed skin while its wings expand. The newly emerged adult slowly pumps liquid into its wings, which takes about an hour. If the wings aren’t fully extended in this time they may be deformed when they harden, preventing flight. If all goes well, the butterfly is soon ready to fly off in search of food and a new generation begins again.
All butterflies play an important role as pollinators and they are an essential element in the wildlife food chain. For example, some insects and birds feed upon butterflies and caterpillars. For that reason, I try to avoid using pesticides, including “safer” insecticidal soaps or homemade concoctions because they can harm the eggs and caterpillars.
When I spot caterpillars on any of my plants, I check one of my bug books to identify them before I do anything. Often, I’ve found that the critters are the offspring of a butterfly or lady beetle and therefore beneficial. When I come across green loopers—moth caterpillars—eating my broccoli and cabbage plants, I pick them off and drop them into a pail of dishwashing suds.
Sacrificing a few leaves on my dill, carrots, fennel or parsley for hungry swallowtail caterpillars is well worth the joy I get watching them move about. Butterfly caterpillars seldom destroy ornamental plants, but some like that of the giant swallowtail (aka orange dog), can damage citrus crops.
Many homeowners try to eliminate wild violets from their lawns and shade gardens. I like them because they are a host plant for the great-spangled fritillary. The butterfly mates in July and lays its eggs in August and September near the base of violets. Once the caterpillars hatch, they eat their eggshells and then hibernate all winter. In spring when the violets leaf out, the caterpillars begin eating them at night and hide under the plants during the day. This butterfly reproduces only once so I like to cultivate violets in my shade garden for them and for me.
After a summer rain, I sometimes spot butterflies standing in shallow puddles on my driveway, on the sidewalk, or on wet, bare soil, where they are “drinking” minerals rather than nectar. Others may visit animal droppings for their mineral diet. You can create a butterfly feeding station by filling a shallow saucer with moist sand and pebbles and placing it on the ground below your flowers.
“Mourning Cloak” Photo Credit: Nina Koziol
Most summertime butterflies live only a week or two. But the mourning cloak, which can live nearly a year, can survive a cold winter by sheltering in piles of branches or leaves or under loose tree bark.
One mild February day when the sun was warm and a little snow still blanketed the ground, I was checking for the first sign of daffodils when a mourning cloak floated past me. It was looking for tree sap—a source of sugar—before it would go back into hiding for another eight weeks. A butterfly in winter … magical, indeed.
Learn More:
The North American Butterfly Association’s web site offers a wealth of information, including regional butterfly garden guides, publications, tips for enhancing your garden and an opportunity to certify your garden as a butterfly habitat.
Read More:
“The Life Cycles of Butterflies: From Egg to Maturity, a Visual Guide to 23 Common Garden Butterflies” by Judy Burris, Wayne Richards. Storey Books.
“Caterpillars in the Field and Garden: A Field Guide to the Butterfly Caterpillars of North America,” by Thomas J. Allen, Jim P. Brock, Jeffrey Glassberg. Oxford University Press.
See it Happen:
Watch National Geographic’s video on the lifecycle of the monarch butterfly.