Blooming occurs in mid- through late summer and after blooming long, relatively thin, rounded follicles are produced that grow uprightly. If you are in a hurry and want a mature plant sooner, a … Swamp milkweed also spreads through rhizomes (roots that grow horizontally from the original plant). A. incarnata is commonly referred to as swamp milkweed because of its association with highly saturated soils in wetlands or areas that are flooded seasonally. White Swamp Milkweed (Asclepias perennis) Shirley Denton . preference for shaded wetland habitats. It likes wet, clay soil, but it also prefers full sun. Standing water is tolerated if it is temporary. My swamp milkweed did the same thing this year (its second year). [2] It grows in damp through wet soils and also is cultivated as a garden plant for its flowers, which attract butterflies and other pollinators with nectar. Swamp milkweed is a flowering mash type plant that provides color and will help provide insect life to any mash or rain garden. Native to North America. They split open in late summer through late fall, releasing seeds attached to silky hairs, which act as parachutes that carry the seeds in wind currents. Swamp milkweed. Range map for Swamp Milkweed (Asclepias incarnata) PLEASE NOTE: A coloured Province or State means this species occurs somewhere in that Province/State. Milkweed seed pods are starting to mature to the point where they can be harvested. Range & Habitat: The native Swamp Milkweed is a fairly common plant that occurs in nearly all counties of Illinois (see Distribution Map). Charitable registration # 10686 8755 RR0001, //