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What is it? Asclepias incarnata, commonly known as the swamp milkweed, is a herbaceous perennial plant.

Native to where?  It is native to North America.

Hardiness Zone: Plants are hardy from USDA Hardiness Zones 3 to 6.

What does it look like? Swamp milkweed plants usually grow about 3 to 4 feet tall, producing small, fragrant, pink to mauve (sometimes white) colored flowers in rounded umbellate groups of blossoms.  

Bloom Time: The plants bloom in early to mid-summer with rose shades from pinks to purples.

Growth Habit: It does not spread aggressively like some other milkweeds. It grows from thick, fleshy, white roots. Typically, its stems are branched and the clump-forming plants emerge in late spring after most other plants have begun growth for the year. After blooming, green follicles, approximately 12 cm (4+3⁄4 in) long, are produced that when ripe, split open. They then release light or dark brown flat seeds that are attached to silver-white, silky hairs which catch the wind. Although Asclepias incarnata plants can survive for up to 20 years, most live only two-five years in gardens. The species is not shade-tolerant and is not a good vegetative competitor.

Growing Conditions: Asclepias incarnata prefer moist locations, will also grow well in medium moisture once they are established, even doing well in wet clay soils and poorly drained soils. 

Environmental Benefits: Host plant to Monarch and Queen butterflies, nectar to many.


Image Sources:

By Teune at the English-language Wikipedia, CC BY-SA 3.0,

By Photo by and (c)2009 Derek Ramsey (Ram-Man) - Self-photographed, GFDL 1.2,

Swamp Milkweed

  • Plant Pickup Day is Saturday, May 18 at Nanny Park, corner of 5th Street and Oak Street in Baraboo, from 9 am to 12 pm. 

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