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Enter the approximate length and width of the area you will be planting and click 'Calculate' to determine how many Asclepias incarnata you will need.

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Correct and successful spacing is complex and depends on project conditions. We encourage you to call us at 877-ECO-PLUG for project specific recommendations and further assistance.

Asclepias incarnata

swamp milkweed

  • Category: Perennial
  • Hardiness Zone: 3-9
  • Height: 3-5 Feet
  • Spread: 2 Feet
  • Spacing: 12-18 Inches
  • Bloom Color: Pink
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One of the most beautiful of native perennials with clusters of upturned pink flowers in June and July. Much underused in average garden conditions! Attracts butterflies of all kinds. Willow-like leaves are 4-5" long. Occurs in floodplains and wet meadows.

Click here to download technical information for growers:
Exposure
Full Sun
Part Sun
Soil Moisture Needs
Average
Moist
Green Infrastructure
Bioretention/Rain Garden
Meadow/Prairie
Wetland Indicator Status
Obligate Wetland (OBL)
Plug Type
Landscape Plug™
Season of Interest (Flowering)
Summer
Late Summer
Propagation Type
Open pollinated
Additional Information about Asclepias incarnata

Asclepias incarnata can be recognized by its clusters of upturned deep pink flowers that bloom in mid-summer. These sit atop an elegant upright, branching stem with smooth willow-like foliage. Its height varies widely depending on soil moisture, soil nutrients and light conditions.

This wetland perennial is broadly distributed across the United States and Canada. Look for it occuring naturally in marshes, swamps, wet meadows and riparian areas.

We've observed that swamp milkweed stays true to its name as an excellent performer in the consistently moist soils of the bioswales and rain garden located in the lowest spots on our property. In our stormwater systems it happily accomodates temporary inundation after major rain events. Like many wetland perennials it will eventually spread rhizamtously to form a colony.

Like other Asclepias species, swamp milkweed is very popular with pollinating insects, attracting a diverse and ample array of butterfly, skipper, fly, wasp and bee species. Even hummingbirds are occasional visitors to its flowers! Its foliage is an important food source not only for the Monarch butterfly but also for the Swamp Milkweed Leaf Beetle and Large Milkweed Bug.

BONAP Map

Growing & Maintenance Tips for Asclepias incarnata

Swamp milkweed, true to its name, prefers consistently moist soil, but performs admirably in average, well-drained gardens as well. Full sun is best and some shade is tolerated, though blooming time and color may suffer.

Gather bouquets of Asclepias all summer long; the long stems are wonderful for cutting and are long-lasting. Sear the ends of the cut stems over a flame to stop the milky sap from leaking out.