perennialN. America Native

Purple Milkweed

The Story

Plant Bio

Asclepias purpurascens, the purple milkweed, is an upright herbaceous perennial native to woodlands and savannas of central and eastern North America. It spreads slowly via underground rhizomes, producing unbranched stems clothed in broad, opposite leaves up to eight inches long.

This species is distinguished by its terminal, rounded umbels of deep rose-pink to dark purple-magenta flowers with prominent light pink hoods. Unlike the aggressive common milkweed, it remains clump-forming and behaves well in a garden border.

Uses & Benefits:

Produces deep magenta-purple flower clusters that contrast with green foliage in naturalistic borders.

Highly deer-resistant once established due to toxic cardiac glycosides in the sap.

Serves as a critical larval host plant for the monarch butterfly and provides nectar for native bees and beneficial insects.

Essentials

At a Glance

Plant Type

Perennial

Height

48"

Width

36"

Light

Full Sun, Partial Sun

Zones

4, 5, 6, 7, 8

Water

Dry to medium

Humidity

Moderate

Lifespan

Perennial

Native To

North America

Toxicity

Toxic if ingested; sap is a skin irritant

Bloom period

Summer – Late summer

In flower about 3 months of the year

Planting

How to Grow

Select a permanent planting site in full sun to partial shade with well-drained sandy, loamy, or clay soil.
Plant bare-root tubers or plugs in spring, taking care not to damage the delicate root system.
Water moderately during the first growing season to establish the root system, avoiding waterlogged conditions.
Leave the plant undisturbed once planted, as its deep root system does not tolerate transplanting.

Pro Tip

Expect a slow start; this species takes three to four years to produce its first flowers from seed or plugs, and it strongly resents root disturbance once established.

Keep It Thriving

Care Guide

Do

Plant in well-drained soil to prevent root rot.
Provide adequate spacing to improve air circulation and prevent powdery mildew.
Mark the planting location clearly, as new shoots emerge late in spring.

Don't

Do not over-fertilize, as this species thrives in low-nutrient soils.
Do not attempt to transplant or divide mature plants unless absolutely necessary.
Do not overwater or plant in low-lying areas where water collects.

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Mulch
Pest Check
Propagate
Spring Cleanup

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Native plant gardensButterfly gardensMeadows and prairiesWoodland edges

Companion Plants

Echinacea purpurea Schizachyrium scoparium Symphyotrichum novae-angliae

Multiply

Propagation Methods

Good to Know

Common Questions

Purple Milkweed questions

What zones can Purple Milkweed grow in?

Purple Milkweed is hardy in USDA Zones 4–8. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Purple Milkweed deer resistant?

Yes — Purple Milkweed is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.

When does Purple Milkweed bloom?

Purple Milkweed typically blooms in summer through late summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Purple Milkweed need full sun?

Purple Milkweed does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.

Is Purple Milkweed drought tolerant?

Yes — once established (usually after the first full season), Purple Milkweed handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.