Butterfly weed (Asclepias tuberosa) is a beautiful native wildflower that is an excellent source of pollen and nectar for beneficial pollinating insects. The genus name Asclepias is derived from the Greek god of medicine, Asklepios, and the species name means a tuberous, taproot.
It prefers to be grown in full sun in dry to medium, well-drained soil. Although butterfly weed is easily grown from seed, these plants will be slow to become established and may take up to 2 or 3 years to bloom. It is best to direct seed into the landscape during the fall, as the seeds need to go through a cold treatment, and then the seedlings will emerge in the spring. Butterfly weed develops a deep taproot; therefore, it does not transplant well. Once it is established in the landscape, it is best to leave it alone.
The mature plant size is 1 to 3 feet tall and 1 to 1½ feet wide. Butterfly weed blooms from June through August and the clustered flowers (called umbels) range in color from vivid orange to orange-yellow. It is one of the few milkweed species that does not exude a milky sap from the leaves or stems. In the fall, a spindle-shaped seed pod is produced that splits open to disperse silky seeds that will float in the wind. The seed pods may be removed before maturing to prevent the seeds from spreading and germinating elsewhere in the yard. I love plants that “travel”, as long as they don’t become invasive, but butterfly weed is welcome to travel all over my landscape!
Butterfly weed is an important source of nectar for many butterflies, including Monarchs, hummingbirds, bees, and other beneficial pollinating insects. Female Monarchs will lay their eggs on the underside of the leaves, which is a vital food source for their caterpillars. Another benefit of planting butterfly weed is that deer and rabbits will leave it alone.
Although there are few diseases or pests that affect butterfly weed, aphids may be a problem. Therefore, use a strong stream of water from a garden hose to wash them off the plants. Be sure to plant in a well-drained area, as root rot will become an issue if the soil is kept too wet. In addition, don’t mulch them heavily in the winter, as a deep, wet mulch layer may cause crown rot.
By planting butterfly weed in your garden, you are not only helping Monarch butterflies and other pollinators, but you are providing yourself with hours of enjoyment watching them visit this beautiful, native perennial