Showy Milkweed
Asclepias speciosa
- Native to:
- Canada, United States
vicki watkins (www.flickr.com) from USA
Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Apocynaceae
- Genus:
- Asclepias
- Species:
- Asclepias speciosa
- USDA Symbol:
- ASSP
Growth Characteristics
- Life Cycle:
- Perennial
- Growth Habit:
- Forb/herb
- Height:
- 150 cm
- Light Requirements:
- Full Sun
- Drought Tolerance:
- Medium
- Bloom Months:
- may,jun,jul,aug
- Bloom Colors:
- pink, purple, white
Wildlife Benefits
- Bees:
- ★☆☆☆☆ Documented bee visitation (GBIF)
- Butterflies & Moths:
- ★☆☆☆☆ Documented Lepidoptera association (GBIF)
- Caterpillars:
- ★☆☆☆☆ Recorded caterpillar host plant (HOSTS Database)
Keystone Species Ranking
- Caterpillar Keystone:
- ★★☆☆☆ Butterfly & moth species supported by this genus (NWF)
Host Plant for Caterpillars
Reported Fauna Sightings
Garden & Ecology Notes
- Wildlife Value:
- bees, butterflies, hummingbirds, native bees
- Deer Resistant:
- Yes
- Fragrant:
- Yes
- Fall Color:
- yellow
- Fire Ecology:
- Fire adapted — tolerates or benefits from fire
- Fire Notes:
- Resprouts vigorously from deep rhizomes after fire. Benefits from periodic disturbance including fire which reduces competition and stimulates flowering.
Soil Requirements
- Soil Type:
- well-drained, sandy or loamy soil
- pH:
- 6.0 - 8.0 (slightly acidic to neutral)
- Drainage:
- excellent drainage required
- Moisture:
- dry to moderate
- Notes:
- native to open, sunny areas with poor soil
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 30–60 days
- Germination Time:
- 7–30 days
- Notes:
- Seeds require light for germination and benefit from cold-moist stratification. Can be direct seeded in fall or stratified and sown in spring.
The above propagation data sourced from Claude AI
Pre-treatment: Seeds are stored in cool-dry conditions with temperatures of approximately 10° C (50° F) and relative humidity of 20 to 30%. Some seeds may require a cold stratification treatment for germination, but others may not. Some seeds are soaked in a 1% hydrogen peroxide solution for 24 hours, rinsed, and placed in water for an additional 24 hours, then refrigerated at 1 to 3 °C for 45 days.
Establishment: There are variations in the pre-treatment and establishment protocols among different sources. The germination rate and time range are also variable. The plant is native to mesic places in western North America from British Columbia to Manitoba and south to Texas.
Source: npn.rngr.net
ORGHPS Germination Guide: Sow @ 4C for 3 weeks, then place @ 20C.