Purple Milkweed
Asclepias purpurascens L.
The most intensely colored milkweed in eastern North America, with deep magenta-purple flower heads held upright above broad leaves, blooming a few weeks before common milkweed. Uncommon and declining nearly everywhere, and worth every effort to establish.
- Height
- 2 ft–4 ft
- Spread
- 1.5 ft–2.5 ft
- Flowers
- purple, magenta
- Bloom
- May to July
- Light
- Full sun, Part shade
- Soil moisture
- Average, Dry
- USDA zones
- 3–8
- Leaves
- Opposite, ovate
- Sap
- Milky latex
- Roots
- Deep taproot, resents transplanting
- Stratification
- 30 days cold-moist
- Range
- 35 states
When it flowers
Purple Milkweed blooms May to July, peaking in June.
How to identify it
- Flowers are a saturated purple-magenta, far darker than the dusty pink of common milkweed.
- Clusters are held erect at the top of the stem, not drooping.
- Blooms noticeably earlier than common milkweed.
- Leaves broad with a short abrupt tip, downy underneath.
Unfamiliar words are in the glossary, and the identification key will narrow a plant down from what you can see.
The parts that identify it
Ecology and wildlife value
A species of woodland edges, savannas and open thickets, declining because fire suppression has closed those habitats. Listed as rare, threatened or endangered in more than a dozen states.
Monarchs are not the only thing that will find it. Expect large milkweed bugs on ripening pods, oleander aphids on the stems, red milkweed beetles at the flowers and, in late summer, milkweed tussock moths. The flowers are a heavy nectar source, so bumble bees and large wasps work them hard, and they are the ones that actually move the pollen. Everything that lives on milkweed.
Growing purple milkweed
Excellent in a garden: upright, non-running and spectacular in flower. Tolerates part shade. Slow from seed and slow to establish; give it three years before judging it.
Seed needs about 30 days of cold-moist stratification. Deep taproot, resents transplanting. See how to plant milkweed seed for the full method.
Cautions
Standard milkweed cautions. Never dig plants from the wild. More on milkweed toxicity.
Where purple milkweed grows
Recorded in 35 states: Alabama, Arkansas, Connecticut, District of Columbia, Delaware, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Maryland, Maine, Michigan, Minnesota, Missouri, Mississippi, North Carolina, Nebraska, New Hampshire, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Virginia, Vermont, Wisconsin, West Virginia.
County records from USDA PLANTS, public domain. Cross-check against BONAP and your regional flora before making management decisions.
Frequently asked questions
What is the prettiest milkweed?
Purple milkweed (A. purpurascens) gets most votes for flower color, a deep magenta unmatched in the genus, with showy milkweed and butterfly weed close behind.
References and further reading
Names, ranges and conservation status here are drawn from the databases below. Where those disagree with a regional flora, trust the flora.
- Plants of the World Online 94577-1. Royal Botanic Gardens, Kew. Accepted name, authorship and global distribution.
- GBIF 3170271. Global Biodiversity Information Facility. Aggregated occurrence records.
- iNaturalist 125380. Community observations, photographs and phenology.
- Wikipedia. General-audience article on this species.
- BONAP county distribution map. Biota of North America Program. County-level range map.
- NatureServe Explorer. Conservation status ranks at global and state level.
- World Flora Online. Nomenclature and synonymy.
- Woodson, R. E. (1954). The North American species of Asclepias L.. Annals of the Missouri Botanical Garden 41(1): 1–211. The monograph the modern taxonomy of the genus still rests on. View
- Flora of North America Editorial Committee (eds.) (2026). Flora of North America North of Mexico. Oxford University Press, New York and Oxford. Accepted names, keys and descriptions for the North American flora. View
- Royal Botanic Gardens, Kew (2026). Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Nomenclature and global distribution, keyed to IPNI name identifiers. View
- Kartesz, J. T. (Biota of North America Program) (2026). North American Plant Atlas. BONAP, Chapel Hill, North Carolina. County-level distribution maps, the basis for the ranges generalized here. View
- USDA, NRCS (2026). The PLANTS Database. National Plant Data Team, Greensboro, North Carolina. State-level distribution, wetland status and nomenclature. View
- Agrawal, A. A. (2017). Monarchs and Milkweed: A Migrating Butterfly, a Poisonous Plant, and Their Remarkable Story of Coevolution. Princeton University Press. The standard general account of the milkweed and monarch relationship. View
Cite this page
This page is licensed CC BY 4.0. Quote it, adapt it and reuse it, including commercially, as long as you credit Milkweed USA and link back.
Milkweed USA. (2026). Purple Milkweed (Asclepias purpurascens). Retrieved DATE, from https://milkweedusa.com/species/purple-milkweed/
"Purple Milkweed (Asclepias purpurascens)." Milkweed USA, 2026, https://milkweedusa.com/species/purple-milkweed/. Accessed DATE.
Milkweed USA. "Purple Milkweed (Asclepias purpurascens)." Last modified 2026-08-01. Accessed DATE. https://milkweedusa.com/species/purple-milkweed/.
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title = {Purple Milkweed (Asclepias purpurascens)},
author = {{Milkweed USA}},
year = {2026},
url = {https://milkweedusa.com/species/purple-milkweed/},
note = {Accessed DATE}
}