California Mountain Ash

Sorbus californica

Native to:
United States

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Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Rosaceae
Genus:
Sorbus
Species:
Sorbus californica
USDA Symbol:
SOCA8

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Shrub
Height:
1200 cm
Light Requirements:
Full Sun
Drought Tolerance:
Medium
Bloom Months:
may,jun
Bloom Colors:
white

Wildlife Benefits

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)

Garden & Ecology Notes

Wildlife Value:
birds, small mammals
Fall Color:
red, orange

Soil Requirements

Soil Type:
well-drained, rocky or sandy loam
pH:
5.5 - 7.0 (slightly acidic to neutral)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
native to mountainous regions, prefers open slopes

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

Source: Ontario Rock Garden & Hardy Plant Society

Where to Buy

Nationwide Seller