You’re driving down the road, and you spot a deep orange swatch of color in the roadside vegetation. “Aha, some Clemson student has lost his ball-cap to the wind”, you say. If it’s early to mid-summer, what you probably saw was a very hardy perennial native wildflower with a long, interesting history. This year, our roadsides are liberally sprinkled with butterfly milkweed, Asclepias tuberosa. This beautiful wildflower has been handed an image problem with weed in the common name, as it is not invasive or weedy.

Butterfly milkweed grows from 15 to 36 inches tall, and is topped with large bundles (umbels) of small flowers. The individual flowers are about ¼ inch in diameter, and range from deep yellow through orange to red. The plant is a long-lived perennial with large, deep taproots. In winter, butterfly weed dies back to a crown just under the soil, until it begins to emerge and grow again in April. It likes poor soil, tolerating sandy to clay sites, and very low soil nutrients and soil pH. I have found butterfly weed growing in pH 5.0 soil with only 2 pounds of available phosphorus per acre.

Butterfly weed has made a large impression on every generation that has experienced it. Linnaeus, the great namer of species, assigned it the genus name Asclepias after Asklepios, the Greek god of healing. Native Americans used it medicinally for several maladies. An early common name, pleurisy root, stems from their use of a tea made from the roots to treat lung infections. This same tea also supposedly prevents … ahem… flatulence, thus another common name is windroot. Our parents called it chiggerweed, but there is no evidence that it is any more of a habitat for chiggers than any other plant out there. It does happen to be in showy bloom during the active chigger season, and we need to blame something for all those bites. In early World War II, our aviator fathers and mothers used life preservers filled with the down from milkweed seeds, to help them stay afloat if they came down over water.

Butterfly weed attracts a large number of insects and insect eaters. Several butterfly species, including the magnificent monarch, use this plant as a nectar source for the adults, and a  food source for their caterpillar children. The individual flowers are small and shallow, and many insect species can reach the nectar. A close look at the flowers will reveal several species of bees and flies feeding. Grasshoppers can be found chewing up the flowers. A closer look will reveal several spider species, apparently waiting to pick off the less vigilant bugs. Birds with a nestful of young frequent the neighborhood of butterfly weeds to harvest insects for their growing families.

With all those flowers and pollinating insects, you would think the plant would produce a large amount of seed. But because of all the insect activity, particularly caterpillar and grasshopper feeding, many of the flowers get eaten before they can produce seed-pods (actually called follicles). This is both good and bad news. As flowers are eaten off, the plant senses that no pods are developing and responds by producing a new wave of flowers. Because of this, butterfly weed will produce waves of flowers from June through September.


To put butterfly weed into your landscape, pick a well-drained site with at least a half day of full sun. In April or early October, buy plants from nurseries, or native plant organizations -- Do not give in to the temptation to dig one from a country roadside. You would be removing a beautiful plant from public view, and the chances are very small that it will survive. Dig a hole just a bit bigger than the root ball, but deep. Gently remove most of the soil from the root ball, saving as many roots as possible, particularly the main root. You can mix in a small amount of the soil mix from the pot, but mixing in too much potting soil will interfere with water movement into the root zone from the native soil surrounding the hole. It never hurts to mix in a half cup of topsoil from a local broomsedge field. This assures that the appropriate friendly fungi will be present in the root zone of your new friend. Place the root ball in the hole, with an eye to having the base of the stem end up just above the surrounding surface on the site. Firm the soil around the deepest roots, then add more soil and firm that too, in 2 or 3 steps. The idea is to have firmed soil between the sides of the hole and the root ball. This assures that water can move freely from the surrounding soil to the root system. Mound up the soil around the stem to the level that it sat in the pot. Don’t add any fertilizer or lime (you might be creating problems for the plant), and if you mulch, leave an open gap around the base of the stem. Mulch around the stem can cause excessive humidity, thus allowing fungi to attack the energy-filled crown and taproot. If drought conditions prevail during the first six weeks after transplanting, the plant should be lightly watered weekly. Don’t over-water, as this plant naturally seeks out dry soil sites, and prolonged wet soil around the roots will kill it.

In late fall, butterfly weed dies back to a crown just under the soil, so in winter it will be invisible. Be sure to mark the planting site with some sort of permanent marker, so as not to forget it, and dig it up by mistake to plant another plant in that “bare spot.” Good companion plants for butterfly weed include native grasses such as silky oatgrass (Danthonia sericea), and little bluestem (Schizachyrium scoparium). Native asters and legumes such as Baptisia species also make good companions. The term weed in the common name can be misleading, as this native plant has no potential to become invasive and weedy.

If you wish to assure that your plant will produce some seeds, make a canopy of ½ inch wire grid (hardware cloth) and enclose part of the plant under the canopy. This will restrict access of egg-laying butterflies to part of the plant, and pod formation can proceed. After pod formation gets underway, remove all but 2-3 pods per branch to insure the plant can supply enough energy to fill the fruit. When the pods begin to turn brown, make a ring of a plastic wire tie that is small enough that it doesn’t pass over the widest part of the pod. Then, when the pod matures and splits naturally, the split is restricted, and all your seed won’t blow away. Butterfly weed and its native companions can add a very natural look to your garden, and many wildlife species will grace your landscape to show their gratitude for your wise choice.