Quick answer: Swamp milkweed (Asclepias incarnata) is native to 37 states. What's commonly sold under this name is the true wild species. It's typically seeds, verified 16 Sep 2026.
Photo: The original uploader was Teune at English Wikipedia., Wikimedia Commons (CC BY-SA 3.0)
Where it's native
Listed in the directory as native to these states. Click a state for its full native-plant guide.
Growing conditions
From the Lady Bird Johnson Wildflower Center Native Plant Database.
| Sun | Sun, Part Shade |
|---|---|
| Water | High water |
| Soil | Rich, wet, muddy to average garden moisture, tolerates mucky clay |
| Bloom | Jun-Oct |
| Height | Up to 5 ft |
| Wildlife value | Larval host for Monarch and Queen, attracts hummingbirds and bees |
All parts toxic only in large quantities; symptoms vomiting, stupor, weakness, spasms. Toxic principle: cardiac glycosides and resinoids.
Buying it
Sold true to the wild species as of the last check (16 Sep 2026), via Amazon.
Sold as: Seeds via Amazon · listing verified 16 Sep 2026
See where to buy →Quick answers about Swamp milkweed
Where is Swamp milkweed native?
Swamp milkweed (Asclepias incarnata) is native to 37 states across the Northeast, Midwest, South and West. Check your state's page in this directory for the full list of plants native where you live.
When does Swamp milkweed bloom?
Swamp milkweed blooms Jun-Oct. Exact timing shifts a few weeks with latitude and elevation.
What growing conditions does Swamp milkweed need?
Light: Sun, Part Shade. Water: High water. Soil: Rich, wet, muddy to average garden moisture, tolerates mucky clay. Mature height: Up to 5 ft.
Is Swamp milkweed good for pollinators and wildlife?
Yes. Wildlife value: Larval host for Monarch and Queen, attracts hummingbirds and bees.
Is Swamp milkweed deer-resistant or drought-tolerant?
Swamp milkweed is deer-resistant and handles wet soil.
Is Swamp milkweed toxic?
All parts toxic only in large quantities; symptoms vomiting, stupor, weakness, spasms. Toxic principle: cardiac glycosides and resinoids.
Where can I buy real Swamp milkweed seed or plants?
We found a listing sold as seeds that names the true species, last checked 16 Sep 2026. Look for the scientific name Asclepias incarnata on any listing.
Similar native plants
Native plants that share growing conditions or range with Swamp milkweed.
- Butterflyweed Asclepias tuberosa
- Sideoats grama Bouteloua curtipendula
- Indiangrass Sorghastrum nutans
- Switchgrass Panicum virgatum
- Little bluestem Schizachyrium scoparium
- Big bluestem Andropogon gerardii
Also listed under
Get the full buying guide
Every pick worth knowing across pollinators, shade, drought and more, in one PDF, with the tradeoffs spelled out. No spam, unsubscribe anytime.