Common Milkweed (Asclepias syriaca) is a rough, weedy perennial which commonly occurs in fields, open woods, waste areas, roadsides and along railroad tracks. It typically grows 3-4 feet (less frequently to 6 feet) tall on stout, upright stems with thick, broad-oblong, reddish-veined, light green leaves (to 8 inches long). Domed, slightly drooping clusters (umbels) of fragrant, pinkish -purple flowers appear mostly in the upper leaf axils over a long bloom period from late spring well into summer. Stems and leaves exude a milky sap when cut or bruised. Flowers give way to prominent, warty seed pods (2-4 inches long) which split open when ripe releasing their numerous silky-tailed seeds for dispersal by the wind. Seed pods are valued in dried flower arrangements. Flowers are a nectar source for many butterflies and leaves are a food source for monarch butterfly caterpillars.
The preference is full sun, rich loamy soil, and mesic conditions, but this robust plant can tolerate a variety of situations, including partial sun and a high clay or sand content in the soil. Under ideal conditions, Common Milkweed can become 6 feet tall and spread aggressively, but it is more typically about 3-4 feet tall. This plant is very easy to grow once it becomes established. Habitats include moist to dry black soil prairies, sand prairies, sand dunes along lake shores, thickets, woodland borders, fields and pastures, abandoned fields, vacant lots, fence rows, and areas along railroads and roadsides. This plant is a colonizer of disturbed areas in both natural and developed habitats.