Plant Preference/Growing Conditions:

Swamp Milkweed is best grown in full sun to part shade. They prefer rich, muddy soil, especially those of the clay variety.

Growth Habit/Description:

Herbaceous perennial plant that is common in many wet areas. Usually averaging up to 5' in height.  Leaves long (between 2.75"-6") and narrow (between 0.5''-1'') and are opposite and pinnate with a coarse texture and colored dark green.  Edges of leaves that get more sunlight often shift to a purple color. Flowers are small, situated in clusters whose color varies between light pink and light purple. Long (4'') pod-like fruit that is narrow like the leaves. Seeds are brown. 

Bloom Season:

Blooms through June, July, August, September, and October. Flowers vary in shades of light pink and light purple.

Fall and/or Winter Interest?

No. 

Host Plant for Caterpillars?

Yes. Swamp Milkweed plays host to Monarch and Queen larvae. 

Other Known Ecological Value?

Yes.   Provides food for adult Monarch butterflies and is an important nectar source for native bees and wasps. 

Origin of Name:  The genus name comes from the Greek god of medicine, Asklepios and the species name from the Latin words carn and atus, which describes the fleshy pink color that Swamp Milkweed flowers occasionally take. 

Related Plant Species:  Swamp Milkweed (Asclepias incarnata) has a few relatives, such as Asclepias perennis, which is also commonly called Swamp Milkweed and has minor differences in its color and which butterflies and bees are attracted.

Use For Food/Medicine: All parts of Swamp Milkweed can induce vomiting and diarrhea, so while not commonly used culinarily, the roots have been used to make a medicinal tea. The tea was used in small quantities to purge the body (i.e., ritualistic cleanses) and to expel various parasites. 

Asclepias incarnata (Apocynaceae) image 50207 at. (n.d.). http://tcf.bh.cornell.edu/imgs/robbin/sq/Apocynaceae_Asclepias_incarnata_50207.html

Asclepias incarnata (Marsh Milkweed, Swamp Butterfly Weed, Swamp Milkweed) | North Carolina Extension Gardener Plant Toolbox. (n.d.). https://plants.ces.ncsu.edu/plants/asclepias-incarnata/

Critters, C. (2019, December 7). What is Monarch Butterfly DISEASE Ophryocystis elektroscirrha? Crazy Plants Crazy Critters. https://crazycrittersinc.com/what-is-monarch-butterfly-disease-ophryocystis-elektroscirrha/

Flawildflowers. (2022a). Swamp milkweed. Florida Wildflower Foundation. https://www.flawildflowers.org/flower-friday-asclepias-perennis/

Flawildflowers. (2022b). Swamp milkweed. Florida Wildflower Foundation. https://www.flawildflowers.org/flower-friday-asclepias-incarnata/

Lady Bird Johnson Wildflower Center - The University of Texas at Austin. (n.d.-a). https://www.wildflower.org/plants/result.php?id_plant=ECPA

Lady Bird Johnson Wildflower Center - The University of Texas at Austin. (n.d.-b). https://www.wildflower.org/plants/result.php?id_plant=ASIN

Swamp milkweed. (n.d.). https://www.fs.usda.gov/wildflowers/plant-of-the-week/asclepias_incarnata.shtml

USDA Plants Database. (n.d.). https://plants.sc.egov.usda.gov/home/plantProfile?symbol=ASIN

Last edited by Lukas Bowler, September 2023.