Description

Asclepias tuberosa is a clump-forming wildflower with attractive, lance-shaped, dark green leaves. Mature plants will produce several hairy, erect stems that are branched in their upper portion. These flowering stalks will grow to a height of 3', and are topped with several dense clusters (umbels) of flowers that are typically orange, but can range in color from shades of yellow to shades of red. The ensuing seed pods are elliptical, up to 6" long, and seem over-sized for the plant. They are very ornamental in their own right, and are often used in dried flower arrangements. At maturity, these pods split open from the center, and release a hundreds of silky, winged seeds to be dispersed by the wind.

Cultivation

The native range of Asclepias tuberosa is extensive, and encompasses the eastern half of the US, and then some. It produces a tuberous taproot, making the plant drought tolerant and well adapted to poor, sandy, and rocky soils. It is easy to grow in typical garden conditions, the only soil requirement is that it should be well-drained. It does best in a bright location, in full to part-sun. It is best planted in groups, because clumps are slow to form, and self-seeded plants will take years to reach flowering maturity. Bloom period is from early to mid-summer, with an occasional secondary bloom period from late summer to early fall. Flowers are long-lived. Both cold hardy, and heat tolerant: zones 4-10

Propagation

Due to its taproot, butterfly milkweed does not transplant well. However, the most effective way to propagate it is by digging up a mature plant in fall, and making 2" long root cuttings. It is easy to propagate from seed, but it requires a lot of patience: plants will take at least 3 years to reach flowering maturity.

Additional Notes

Asclepias tuberosa will attract a variety of pollinators, including bees and butterflies, and is a larval host for the endangered Monarch. It can also be considered deer resistant.

The roots have long been known to ease pulmonary ailments, hence the alternate common name: pleurisy root. However, they shouldn't be considered edible, and are even toxic if ingested in large quantity.

The genus common name Milkweed is somewhat of a misnomer when it comes to A. tuberosa, because the stems do not produce the milky sap typical of other species within the genus.