Asclepias incarnata
swamp milkweed
A thick-stemmed perennial with dense stems and narrow, mid-green leaves up to 15cm long. Clusters of dark purplish-pink flowers are produced from the upper part of the stems from mid-summer to early autumn, followed by narrow, upright seed pods up to 7cm long, green at first then turning pale brown before splitting to release the seeds with their parachutes
Buy this plant
Size
Ultimate height
1–1.5 metresTime to ultimate height
2–5 yearsUltimate spread
0.1–0.5 metresGrowing conditions
Moisture
Moist but well–drained, Poorly–drainedpH
Acid, Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Green | |||
|---|---|---|---|---|
| Summer | Pink | Green | ||
| Autumn | Pink | Green | Green Brown | |
| Winter |
Position
- Full sun
Aspect
South–facing or West–facing
Exposure
Sheltered Hardiness
H4Botanical details
- Family
- Apocynaceae
- Native to the UK
- No
- Foliage
- Deciduous
- Habit
- Bushy
- Potentially harmful
- Harmful if eaten. Wear gloves and other protective equipment when handling
- Genus
Asclepias can be evergreen or deciduous perennials or subshrubs, with simple, entire leaves and umbel-like clusters of small, distinctively shaped flowers followed by paired fruits containing seeds embedded in silky fibres
- Name status
Correct
- Plant range
- NE & SE USA
How to grow
Cultivation
Grow outdoors in moist, fertile, loamy soil in full sun. Will thrive near a pond or stream
Propagation
Propagate by seed or by division, or root basal cuttings in spring
Suggested planting locations and garden types
- Cottage and informal garden
- Prairie planting
Pruning
No pruning required
Pests
Generally pest-free
Diseases
Generally disease-free
Get involved
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.