perennial · design plant record

Asclepias incarnata

Swamp milkweed

A tall summer-flowering layer for a reliably moist planting.

Photographs show the source plant or captioned cultivar, season and setting. They do not document one of our illustrative garden layouts as a built project.

Height at maturity

0.91–1.52 m (3–5 ft)

Spread at maturity

0.61–0.91 m (2–3 ft)

Light

Sun / Part shade

Moisture

Moist, draining soil / Wet-soil tolerance (check details)

Source-reported USDA zones

3–9 · verify subzone and cultivar

Principal seasonal role

Autumn, Summer

Fit it to the site

Moist clay or loam, neutral to acidic; occasional wet ground is suitable.

Do not substitute it for dry-site butterfly weed. Wet tolerance does not specify a pond planting depth.

Keep the care in the decision

Keep establishment moisture dependable. Retain suitable access for checking stems, seed pods and host-plant feeding.

Origin & safety checks

Central & E. Canada to W. Central & E. U.S.A.. Confirm local native range and restrictions.

The source flags poisonous parts or harmful exposure. Check the exact plant and household exposure before purchase; no edible or pet-safe use is inferred.

Check current invasive restrictions with your local plant-health or extension authority. For pets, use the exact botanical name in a veterinary toxicity reference; for potential ingestion or exposure, get appropriate professional advice rather than relying on a design guide.