Marsh Milkweed (Asclepias incarnata): A Blast of Color in Wetlands

Swamp Milkweed

This Marsh or Swamp Milkweed (Asclepias incarnata) is one of the most obvious native plants along our shores and in our marshes. Like many milkweeds these are relished by the larvae of Monarch Butterfly (Danaus plexippus) caterpillars.

Other name: Swamp Milkweed, Rose Milkweed, Red Milkweed

Plant Family: Milkweed, Asclepiadaceae

Wetland Indicator Status: OBL

Marsh Milkweed (Asclepias incarnata), perhaps more known as Swamp Milkweed, is one of the prettiest plants you can find at the water’s edge, or deep in the marsh.  Not only are its magenta blooms gorgeous, they smell wonderful too.  If the stems survive the winter, in spring you may see birds tearing off the fibrous outer strips of the stems. It makes great nesting material and great cordage used by Native Americans.  I once made some twine from a single Marsh Milkweed stem and found it impossible to break with my hands.

Like Common Milkweed and others of its family, Marsh Milkweed contains a sticky white sap that oozes out of roots, stems, leaves and flowers when they become damaged.  The sap is mildly toxic and many insects avoid the plant.  However, several insects have evolved to digest the foliage, including the sap.  Some insects like the Monarch Butterfly (Danaus plexippus) become distasteful to predators after eating the plant as a ccaterpillar  The beauty of the Monarch Butterfly is actually a message to predators stating I taste bad, and I’m not good for you.

Marsh Milkweed is an excellent forb for shoreland restorations, rain gardens and wetland restorations, because it is a very attractive and interesting plant.  Planting it is also a way to help the Monarch Butterfly, whose population is in a steep decline from loss of Common and other milkweed species in and near farm fields.  For that reason it is also a good idea to plant Common Milkweed on drier ground.  It is a hardy and attractive plant in its own right.

Marsh Milkweed is most often called Swamp Milkweed, but I prefer “Marsh.”  It seems to roll off the tongue better, and its habitat is more often sunny marshes than shady swamps.

Marsh Milkweed

Marsh Milkweed (Asclepias incarnata) is rises above the sedges and grasses and announces it presence to bees, butterflies and other pollinators in Wisconsin’s wetlands.