Species Native to Missouri
Common Name: common milkweed
Type: Herbaceous perennial
Family: Apocynaceae
Native Range: Eastern North America
Zone: 3 to 9
Height: 2.00 to 3.00 feet
Spread: 0.75 to 1.00 feet
Bloom Time: June to August
Bloom Description: Pink, mauve, white
Sun: Full sun
Water: Dry to medium
Maintenance: Low
Suggested Use: Naturalize
Flower: Showy, Fragrant
Attracts: Butterflies
Fruit: Showy
Tolerate: Deer, Drought, Erosion, Dry Soil, Shallow-Rocky Soil
Culture
Easily grown in average, dry to medium, well-drained soils in full sun. Drought tolerant. Does well in poor, dryish soils. Easily grown from seed, and will self-seed in the landscape if seed pods are not removed prior to splitting open. Can spread somewhat rapidly by rhizomes and may be aggressive for smaller garden areas. Often forms extensive colonies in the wild.
Noteworthy Characteristics
Asclepias syriaca, commonly called common milkweed, is a rough, weedy Missouri native perennial which commonly occurs in fields, open woods, waste areas, roadsides and along railroad tracks throughout the State (Steyermark). It typically grows 3-4' (less frequently to 6') tall on stout, upright stems with thick, broad-oblong, reddish-veined, light green leaves (to 8" 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" 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 larvae (caterpillars).
The charismatic and imperiled monarch butterfly requires milkweed plants in order to survive. Monarchs migrate into the eastern U.S. from Mexico in spring to lay their eggs on milkweed species plants. Caterpillars hatch from the eggs and consume the milkweed plant foliage as food for growth and development. Mature caterpillars will search for a nearby, sheltered location to enter the pupal stage and form a chrysalis. Inside, they will complete metamorphosis and emerge as an adult butterfly in around 2 weeks. Flower nectar is consumed by adult butterflies as a valuable food source. The 4th or 5th generation of monarch butterflies that emerges in August-September will migrate into Mexico to overwinter as adults. Significant declines in monarch butterfly populations in North America over the course of the 21st century are believed by many experts to be caused by a reduction in milkweed due to widespread use of herbicide-tolerant row crops, climate change, and loss of overwinter sites due to habitat destruction.
To support monarch butterflies, plant species of milkweed that are native to your area.
Genus name honors the Greek god Asklepios the god of medicine.
Specific epithet means Syrian.
Problems
No serious insect or disease problems. Rhizomatous spread can be aggressive. Aphids can be problematic but attempting to control them can result in inadvertent harm to monarch caterpillars and other beneficial insects.
Uses
Butterfly gardens, meadows, prairies, or naturalized/native plant areas. This plant is considered by many gardeners to be too vigorous and weedy for borders.