Common milkweed
Asclepias syriaca · Apocynaceae
The gardener's calendar
Ideal time to plant common milkweed: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Common name
- Showy milkweed, Swamp milkweed
- Family
- Apocynaceae
- Type
- Perennial herb
- Adult size
- 0.9 to 1.5 m in height
- Foliage
- Deciduous, light green, elliptical
- Flowering
- June to August, pink-mauve flowers in umbels
- Hardiness
- Very hardy (zone 3, down to -40°C)
- Origin
- North America
Care
Light exposure
Plant showy milkweed in full sun or partial shade for optimal growth. It tolerates direct exposure very well and will also handle partial shade nicely. The more sunlight you provide, the more abundant and vibrant the flowering will be.
Watering
Water regularly during the first year of establishment to encourage deep root development. Once established, this plant is very tolerant of drought thanks to its taproot. Limit watering after that, except during prolonged dry periods.
Soil
Showy milkweed adapts to most soils, including poor, sandy, or well-draining ones. It prefers rather dry terrain and won't tolerate stagnant moisture. Avoid overly compacted soils and ensure good drainage.
Pruning and cleanup
Cut the plant back to ground level at the end of winter (February-March) before new growth begins. You can also trim lightly during the growing season to maintain a compact shape. Remove spent flowers to extend the blooming period.
Fertilizing
Showy milkweed requires very little fertilizer, or none at all once established. A balanced application in spring will suffice, except in very poor soils. This plant is not demanding when it comes to nutrients.
Diseases and pests
Showy milkweed is very hardy and rarely subject to diseases. Occasionally watch for aphids or spider mites, especially early in the season. Excess moisture can promote root rot or fungal diseases.
Did you know?
Showy milkweed was traditionally used by Native Americans and early colonists for multiple purposes: its fibers were used to fill clothing and cushions, and its feathery seeds, packaged in a sort of natural cotton, would fly away spectacularly at the slightest breeze. This characteristic gave it its common name and makes it a valuable ally for butterfly and pollinator gardens.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
- Lesser periwinkleVinca minor
- Greater periwinkleVinca major
- OleanderNerium oleander
- Asiatic jasmineTrachelospermum asiaticum
- Star jasmineTrachelospermum jasminoides
- AmatunguluCarissa macrocarpa
Tips generated and checked by Viridia — adapt them to your local climate.