Whorled Milkweed, Asclepias verticillata

Whorled Milkweed

Asclepias verticillata

Sun Shade:
Bloom Time: Summer
Zones: 3, 4, 5
Soil Conditions: Loam, Sand
Soil Moisture: Dry
Color: Green, White
Fragrance: No
Height: 1 - 2 feet
Spacing: 1 foot


Whorled Milkweed (Asclepias verticillata) is an upright perennial that typically grows to 2 ½ feet tall on simple, usually unbranched stems clad with long, narrow, sessile, needle-like, linear leaves with revolute margins arranged in whorls of 3 to 6 at each node along the length of the stems. Stems ooze a milky sap when cut or broken. Flowers bloom in small clusters (umbellate cymes of 3-20 flowers) in the upper leaf axils and stem ends between June and September. Flowers are fragrant. Each tiny flower has a 5 lobed calyx, 5 greenish-white corolla lobes and 5 white hoods with incurved horns protruding from each hood. Flowers give way to smooth, narrow seed pods which split open when ripe releasing numerous silky-tailed seeds for dispersal by the wind. During hot dry weather, the lower leaves may turn yellow and fall off, or the foliage of the entire plant may become yellowish green.

The blooming period occurs from early to late summer, lasting about 1-2 months. Afterwards, successfully cross-pollinated flowers are replaced by ascending to erect follicles (seedpods that open along one side). These follicles are 3-4 inches long and about ½-inch across; they are narrowly lanceoloid in shape and fairly smooth (lacking warts or soft prickles). At maturity during autumn or winter, these follicles split open to release their seeds to the wind. Mature seeds are about 4-5 mm. long, ovate-flattened in shape, brown, and narrowly winged along their margins; their apices have large tufts of white hair. The root system is fleshy-fibrous and long-rhizomatous. Colonies of clonal plants are often produced from the rhizomes.

Habitats include upland prairies, sand prairies, gravel prairies, hill prairies, openings in rocky upland forests, sandy savannas, limestone glades, rocky bluffs along major rivers, bluegrass meadows, pastures and abandoned fields, grassy slopes along highways, and waste areas. Whorled Milkweed is a pioneer species that prefers open disturbed areas.

Easily grown in average, dry to medium moisture, well-drained soils in full sun. Tolerates part shade. Best in sunny locations with sandy loams. Plants will spread by rhizomes but are not considered invasive.

Plant Notes and Herbal Uses
  Seed pods are valued in dried flower arrangements.
  Monarch butterflies need milkweed plants.
  Easily grown from seed.
  Will self-seed in the landscape if seed pods are not removed prior to splitting open.
  Drought tolerant.
Further Information

 Wisconsin Fruit Trees
 Wisconsin Edible Berry Shrubs
 Widsconsin Edible Plants-Eat On The Wild Side
 8 Dandelion Recipes
 Wisconsin Native Plant Nurseries