Swamp Milkweed
Asclepias incarnata
Last reviewed: July 2026
Swamp Milkweed (Asclepias incarnata) is a native perennial wildflower that blooms pink from June through August across most of the United States. This moisture-loving plant attracts bees, butterflies, and moths to wet meadows and garden borders.
Swamp Milkweed is toxic to dogs and cats.
Listed as toxic by the ASPCA Animal Poison Control Center (opens in new tab) (last reviewed 2026-05-21). If your pet has been exposed, call the ASPCA Animal Poison Control Center at (888) 426-4435and your veterinarian's emergency line.
Pollinator Patch flags toxic plants so you can choose a pet-safe native alternative for your yard.
Swamp Milkweed is listed as toxic to grazing livestock (cattle, sheep, and goats) at a moderate level by the USDA PLANTS Database (opens in new tab). This is a livestock indicator and is separate from pet toxicity.
Light
part sun
Water
high
Size
24"–60" H × 12"–24" W
Bloom
Jun, Jul, Aug
Native to
AL, AR, AZ, CO and 40 more states
Pollinators
bees, butterflies, moths
Deer
Resistant (per Prairie Moon Nursery)
Browse plants for this ecoregion
Swamp milkweed produces clusters of fragrant pink flowers from June through August on sturdy stems that reach 2-5 feet tall. This native perennial thrives in moist conditions and forms attractive clumps over time. The long seed pods that follow the flowers add interest through fall before the plant goes dormant in winter.
Growing Swamp Milkweed
Grow Swamp Milkweed in part sun and high water. Mature plants reach 24 to 60 inches tall and spread 12 to 24 inches wide. Expect moderate maintenance to keep it looking intentional in a front yard.
In an HOA neighborhood
Swamp Milkweed is an HOA-friendly choice in the right placement. Maintenance level: moderate. Tidiness: 3 out of 5.
Works well in: mid zone, backyard only.
- Requires consistently moist soil which may be difficult to maintain
- Can look weedy when dormant in winter
- May self-seed and spread beyond intended area
Wildlife value
Host plant for monarch butterfly, queen butterfly.
Essential host plant for monarch butterfly caterpillars and provides nectar for many butterflies, bees, and moths. The flowers are particularly attractive to monarchs during their summer breeding season.
Common questions
- When does Swamp Milkweed bloom?
- Swamp Milkweed typically blooms from June through August, producing clusters of fragrant pink flowers that attract pollinators.
- What growing conditions does Swamp Milkweed prefer?
- This native milkweed thrives in consistently moist to wet soils and can tolerate full sun to partial shade. It naturally grows in wet meadows, marshes, and along stream banks.
- What pollinators visit Swamp Milkweed?
- Swamp Milkweed attracts a variety of pollinators including native bees, butterflies (especially monarchs), and moths. The nectar-rich flowers are particularly valuable for monarch butterfly conservation.
- Where is Swamp Milkweed native?
- Swamp Milkweed is native to most of the continental United States, from coast to coast, including wetland areas in both eastern and western regions.
- Is Swamp Milkweed toxic to dogs?
- Yes. Swamp Milkweed is listed as toxic to dogs by the ASPCA Animal Poison Control Center (aspca.org). If your pet has been exposed, call the ASPCA Animal Poison Control Center at (888) 426-4435.
- Is Swamp Milkweed toxic to cats?
- Yes. Swamp Milkweed is listed as toxic to cats by the ASPCA Animal Poison Control Center (aspca.org). If your cat has been exposed, call the ASPCA Animal Poison Control Center at (888) 426-4435.
- Is Swamp Milkweed toxic to livestock?
- Swamp Milkweed is listed as toxic to grazing livestock such as cattle, sheep, and goats (moderate severity) by the USDA PLANTS Database. This is separate from pet (dog and cat) toxicity.
- Is Swamp Milkweed HOA-friendly?
- Swamp Milkweed is generally an HOA-friendly choice in the right placement, with moderate maintenance.
Native range data from the USDA PLANTS Database and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
Pollinator Patch flags toxic plants like Swamp Milkweed and shows pet-safe natives for your ecoregion instead.
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