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For Your Garden - July 2014

Have you been meaning to add a few native plants to your garden? Native plants provide beauty as well as food and shelter for wildlife. Native species are adapted to the Illinois climate. They require little or no watering and are resistant to drought, insects and most diseases. Because they are perennials, you can welcome their presence year after year.

swamp milkweed (Asclepias incarnata)

Swamp milkweed grows in marshes, wet fields and along the shores of ponds, lakes and streams throughout Illinois. Flowering occurs from June through August. The flowers are dark pink and may have a white center. Flowers are produced in a cluster at the stem tip, with each flower on its own stalk. Although there are many flowers in a cluster, usually only a few of them are pollinated. The pollinated flowers develop into large pods that contain seeds attached to silky plumes. These plants may grow to nearly five feet tall. Their leaves are arranged oppositely on the stem. Each leaf may be up to six inches long and one inch wide. The sap of swamp milkweed is white. Monarch butterfly larvae are among the few organisms that are able to eat milkweed leaves. Many pollinators are attracted to the flowers, however.

Classification and taxonomy are based on Mohlenbrock, Robert H. 2014. Vascular flora of Illinois: A field guide. Fourth edition. Southern Illinois University Press, Carbondale. 536 pp.

Illinois Range

Native Plant Information

For more information about Illinois native plants, visit our Native Habitat Descriptions, Requirements, and Plant Lists page. The following publications are available from the IDNR on our publications page.


​Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Gentianales
Family: Asclepiadaceae

Illinois Status: common, native