Students for Stewardship The Cork Board
← Back to the library

Purple Milkweed

Asclepias purpurascens (as-KLEE-pee-as pur-pur-ESS-kenz)

Family: Apocynaceae Native Herbaceous (3-15 ft)

Purple Milkweed is a perennial wildflower native to eastern and central USA. It is a rare species in NC but can be found in swampy areas to dry woodlands and meadows of the Piedmont and mountains. The plant grows 2 to 3 feet tall and wide in full sun to partial shade. It prefers moist well-drained garden soils. The plant is similar to common milkweed but the flowers are a deeper purple to rose-pink. They occur in clusters from May to July and attract bees and butterflies. The leaves are host to the monarch butterfly larvae. This plant can spread aggressively by seeds and rhizomes and is not appropriate for small gardens. It is easy to grow in average moist to dry well-drained soils in full sun. It is drought and deer tolerant. Use in naturalized areas as meadows, native plantings, wild gardens, along streams or ponds and to attract butterflies. Insects, Diseases, and Other Plant Problems: No significant disease problems. Most common milkweed pests (aphids, milkweed beetles, Monarch larvae, and milkweed tussock moth larvae) are not problematic, but both large and small milkweed bugs can be very damaging to seed pods.

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 62 attributes.

How it fits the guild

Guild layer 4 - Herbaceous (3-15 ft)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Full plant profile

Growing Conditions
Plant type
Herbaceous Perennial; Native Plant; Wildflower
Life cycle
Perennial
USDA zones
3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
Light
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Clay; Loam (Silt); Sand; Shallow Rocky
Soil drainage
Moist
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 2 ft. 0 in. - 3 ft. 0 in. | Width: 1 ft. 0 in. - 3 ft. 0 in.
Growth rate
Medium
Maintenance
High
Canopy layer
4 - Herbaceous (3-15 ft)
Form & Appearance
Habit / form
Erect
Texture
Medium
Leaf color
Green
Leaf type
Simple
Leaf arrangement
Opposite
Leaf shape
Lanceolate; Oblong; Ovate
Leaf margin
Entire; Undulate
Leaf size
> 6 inches long, 1-3 inches wide
Hairs present
Yes
Leaf detail
Leaves are 4-8 inches long and 2-3 inches across, ovate to oblong-lanceolate and opposite. Dark green above and slightly pubescent below. Margins may be wavy and curl upward.
Flower color
Pink; Purple/Lavender
Flower value
Showy
Flower form
Umbel
Flower shape
Tubular
Flower size
< 1 inch
Flower detail
3/4 inch deep rose-pink to purple flowers with 5 petals appear in clusters 2-3 inches across May-July.
Bloom time
Summer
Fruit type
Follicle
Fruit value
Good Dried
Fruit size
> 3 inches long, < 1 inch wide
Fruit detail
Up to 6" long and 1" across smooth seed pods with short hairs split open when mature to release numerous seeds with tufts of white hairs for dispersal by the wind July to October.
Stem detail
Erect green stems may have fine hairs and ooze a milky sap when broken.
Wildlife & Ecology
Native status
Native
Origin
Eastern North America
Wildlife value
Nectar and larval host plant that attracts bees, butterflies (notably Monarchs), hummingbirds (milkweeds are a source of insects as well as nectar), moths (especially milkweed tussock moths and their larvae), pollinators, predatory Insects, and specialized bees.
Attracts
Bees; Butterflies; Hummingbirds; Pollinators
Food & Medicine
Harvest time
Fall; Summer
Fruit type
Follicle
Landscape Use
Landscape location
Meadow; Naturalized Area; Pond; Slope/Bank; Woodland
Landscape theme
Butterfly Garden; Native Garden; Pollinator Garden
Garden tags
#swamps #NC native #native wildflower #food source herbage #larval host plant #food source nectar #food source pollen #food source summer #food source fall #wet soils tolerant #bird friendly #FACU Piedmont Mountains #problem for dogs #problem for horses #problem for cats #pink flowers #drought tolerant #Audubon #full sun tolerant #Coastal FACU #th-sound #NC Native Pollinator Plant #woodland #weedy
Problems & Resistance
Insect problems
Milkweed Bug; Aphids on Ornamental Landscape Plants
Problems
Problem for Cats; Problem for Dogs; Problem for Horses; Weedy
Resistant to
Drought; Dry Soil; Erosion; Poor Soil
Poison severity
Low
Poison symptoms
Can cause stomach upset, nausea, vomiting, abdominal pain, diarrhea, weakness, lethargy, and confusion if eaten in quantity. Milky sap can cause contact dermatitis and eye irritation
Toxic principle
Cardiac glycoside
Contact dermatitis
Yes
Toxicity summary
Low severity poison; contact dermatitis

Planted at Hunnicutt

Nobody’s planted this one yet.