Swamp milkweed is an herbaceous perennial native to central and eastern United States and tends to grow in wet sites along streams, ponds, or bogs.
Plant swamp milkweed in full sun to partial shade in soils with neutral to acidic pH. It is native to wet sites but adapts to drier sites in moist clay or loam soils.
The fragrant umbelled clusters of flowers range in color from soft mauve to pink to reddish-violet. Five tiny delicate petals are crowned with five nectar cups that are crucial in its intricate pollination. Within each small cup is an upward curving horn. An insect landing on the blossom slips on the horn. Its leg goes into a slit between the cups and picks up pollen.
The attractive pink to rose-purple flowers mature in mid-spring and last into early fall. The seed pods split open to release seeds that float on the wind. Milkweed is an important food source for Monarch butterfly caterpillars and the flowers are visited by many pollinators.
Use as an accent or border in a meadow, native, or pollinator garden. It will be at home in a naturalized area or along a pond or stream where it can grow up to 5 feet tall and spread 2 to 3 feet wide.
This plant was selected as the 2005 NC Wildflower of the Year, a program managed by the North Carolina Botanical Garden.