Western Mountain Ash
Sorbus sitchensis
- Native to:
- Canada, United States
Walter Siegmund (talk)
Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Rosaceae
- Genus:
- Sorbus
- Species:
- Sorbus sitchensis
- USDA Symbol:
- SOSI2
Growth Characteristics
- Life Cycle:
- Perennial
- Growth Habit:
- Shrub , Tree
- Height:
- 1200 cm
- Light Requirements:
- Full Sun,Part Shade,Shade
- Drought Tolerance:
- Medium
- Bloom Months:
- may,jun
- Bloom Colors:
- white
Wildlife Benefits
- Bees:
- ★☆☆☆☆ Documented bee visitation (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
Acronicta superans, Barnes' dagger moth (Acronicta barnesii), Ceranemota crumbi, Radcliffe's dagger moth (Acronicta radcliffei), Western tent caterpillar (Malacosoma californica)
Reported Fauna Sightings
Bees: Black-tailed bumble (Bombus melanopygus)
Garden & Ecology Notes
- Wildlife Value:
- birds, small mammals
- Fall Color:
- red, orange
Soil Requirements
- Soil Type:
- moist, well-drained, rocky or sandy soil
- pH:
- 5.0 - 7.0 (slightly acidic to neutral)
- Drainage:
- excellent drainage required
- Moisture:
- consistently moist
- Notes:
- prefers cool, mountainous regions
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 60–90 days
- Germination Time:
- 30–60 days
- Notes:
- Seeds require cold stratification for 60-90 days to break dormancy.
Pre-treatment: Cold-moist stratification for 30 days at 1–5°C (34–41°F).; then Cold-moist stratification for 60 days.
Source: Claude AI
ORGHPS Germination Guide: Place on damp paper towel in plastic bag for 6 weeks in fridge - should germinate in cold
Where to Buy
Nationwide Seller
- Sheffield's Seed (seeds)