Asclepias, Genus, purpurascens, Species,
- Genus & species
purple milkweed
Overview
Asclepias purpurascens is an upright herbaceous perennial growing 2 to 3 feet (60 to 90 cm) tall from a deep root, with unbranched stems and milky sap. The opposite, oval leaves are 4 to 8 inches (10 to 20 cm) long, with a smooth upper surface and downy underside. In late spring and early summer it bears rounded umbels of deep rose to purple flowers at the stem tip and upper leaf axils, each umbel 2 to 3 inches (5 to 8 cm) across. The flowers deepen in color as they age and give way to upright, narrow seed pods 4 to 6 inches (10 to 15 cm) long that split to release silk-tufted seeds. Unlike common milkweed, it tolerates light shade and grows at woodland edges and in moist prairies of the eastern and central United States. It serves as a larval host for monarch butterflies and a nectar source for many insects. All parts contain cardiac glycosides that are toxic if eaten. It is slow to establish and resents transplanting once the deep root forms.
Native Range
Native to the eastern and central United States, from New England and the Great Lakes south to the Gulf and west to the Great Plains. It grows at woodland edges, in open woods, moist prairies, and along streams.Suggested Uses
Used in native pollinator gardens, woodland edges, and moist prairie or meadow plantings. It serves as a larval host for monarch butterflies and a nectar source for bees and butterflies. Its tolerance of light shade suits plantings that other milkweeds will not take.How to Identify
Appearance
Size & Dimensions
Height2' - 3'
Width/Spread1' - 2'
Bloom Information
Flowering occurs in late spring and early summer, generally May through July. Rounded umbels of deep rose to purple flowers open at the stem tip and upper axils. Each cluster lasts about 2 to 3 weeks and darkens with age. Seed pods ripen through late summer.
Detailed Descriptions
Foliage Description
greenGrowing Conditions
Sun Requirements
Requires 4-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grow in full sun to part shade in moist, well-drained soil. Asclepias purpurascens accepts loam, sand, or clay with a pH from 6.0 to 7.5 and tolerates more shade and moisture than most milkweeds. Water during establishment, then reduce, since the deep root carries the plant through dry spells. It is hardy in USDA zones 3 through 8. The plant is slow to settle in and may take two or three years to flower well. All parts are toxic if eaten, due to cardiac glycosides.Pruning
Cut the dead stems to the ground in late winter or early spring. Leaving the seed pods allows self-sowing, or they can be removed before they split. No other routine pruning is needed. The plant resprouts from the crown each spring.Pruning Schedule
Prune: February–March
winter
