common milkweed

Asclepias syriaca (common milkweed). A member of the Asclepiadaceae native to southern Canada and the eastern United States, east of the Rocky Mountains, this species is one of the more commonly encountered milkweeds growing along roadsides, in old fields, and in degraded prairies.

Growing up to 6-feet tall, common milkweeds blooms in the early summer with fragrant, nectariferous rose-to-pink flowers on pendulate cymes originating at nodes along the stem of the plant. The characteristic milky white latex sap of the plant contains several types of glycocides and is known to be toxic to many insects and animals.

While producing a beautiful flower, the ecological importance of common milkweed far outweighs its aesthetic contributions. Asclepias syriaca is a key host for at least six insects: red milkweed beetle (Tetraopes tetrophtalmus), large milkweed bug (Oncopeltus fasciatus), milkweed leaf beetle (Labidomera clivicollis), small milkweed bug (Lygaeus kalmii), a species of weevil (Rhyssomatus lineaticollis), and the monarch butterfly (Danaus plexippus). Considerable recent press has been given to the role of common milkweed in the lifecycle of the monarch butterfly.

Common milkweed plays an important role in supporting local pollinators, such as Apis wellifera (Western honeybee) and Bombus species (bubble bees).  Common milkweed will produce large, tear-drop shaped pods in the fall. These pods can be harvested and the seed contained therein used to propagate more A. syriaca plants. Pods should be collected 1-2 days prior to opening, dried in a paper bag, and the small brown seeds dried and stored in a cool, dry place. Seeds can be germinated indoors during the late winter/early spring months, ideally 4-8 weeks prior to the final frost of the winter. Start seeds in propagation trays under artificial light, keeping the soil temperature below 80 degrees F. Seeds will germinate and once seedlings reach 3-6 inches in height, they are ready to be transplanted outdoors. Plant young seedlings outdoors in an appropriate site after the danger of frost has past.

Botanical Name Asclepias syriaca
Common Name common milkweed
Family Apocynaceae
USDA Zone 3 thru 9
Light Requirement Full Sun
Season(s) of interest summer, fall, winter
Height and Spread 2-3ft x 0.75-1ft (60-90cm x 22-30cm)
Flower Color Pink
Attracts Wildlife Provides Food for Birds, Hosts Caterpillars of Butterflies/Moths, Attracts Pollinators,
Additional Information Native to Chicago Region. Provides food for Several Host-Specific Species Including the Monarch Butterfly.
Location in Lurie Garden Southwest Light Plate, Northwest Light Plate, Northeast Light Plate, East Meadow, West Meadow, North Dark Plate, Bird Border-Monroe​


Average Flowering Time