Douglas's Milkvetch
Astragalus douglasii
- Native to:
- Mexico, United States
Walter Siegmund (talk)
Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Fabaceae
- Genus:
- Astragalus
- Species:
- Astragalus douglasii
- USDA Symbol:
- ASDO
Growth Characteristics
- Life Cycle:
- Perennial
- Growth Habit:
- Forb/herb
- Height:
- 100 cm
- Light Requirements:
- Full Sun
- Drought Tolerance:
- Medium
- Bloom Months:
- mar,apr,may,jun
- Bloom Colors:
- purple, pink, lavender
Wildlife Benefits
- Bees:
- ★☆☆☆☆ Documented bee visitation (GBIF)
- Butterflies & Moths:
- ★☆☆☆☆ Documented Lepidoptera association (GBIF)
- Caterpillars:
- ★☆☆☆☆ Recorded caterpillar host plant (HOSTS Database)
Keystone Species Ranking
- Pollen Specialist Bee Keystone:
- ★★★☆☆ Native pollen specialist bee species supported by this genus (NWF)
Host Plant for Caterpillars
Queen Alexandra's Sulphur (Colias alexandra), Western Tailed-Blue (Everes amyntula)
Reported Fauna Sightings
Bees: Two-form bumble bee (Bombus bifarius), Yellow head bumble bee (Bombus flavifrons), Yellow-faced bumble bee (Bombus vosnesenskii)
Garden & Ecology Notes
- Wildlife Value:
- bees, native pollinators, butterflies
- Deer Resistant:
- Yes
Soil Requirements
- Soil Type:
- sandy, well-drained, nutrient-poor soil
- pH:
- 6.0 - 8.0 (neutral to slightly alkaline)
- Drainage:
- excellent drainage required
- Moisture:
- dry to moderate
- Notes:
- native to arid regions, prefers open, sunny areas
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 30–60 days
- Scarification:
- Seed coat scarification required before sowing
- Germination Time:
- 14–30 days
- Notes:
- Seed coat scarification improves germination rates. Seeds benefit from cold-moist stratification after scarification.
The above propagation data sourced from Claude AI
Pre-treatment: Cold-moist stratification for 30 days at 1–5°C (34–41°F).; then Scarify, then cold-moist stratify for 60 days.
Source: Claude AI
ORGHPS Germination Guide: Put in deep pot; protect from damping off