Mountain Ash

Sorbus poteriifolia

Rosaceae · broadleaf deciduous shrub · introduced

Last updated March 8, 2026

Data Coverage 2 of 6 dimensions

Site Data

Threats

Cultivars

Phenology

GDD Thresholds

Puget Sound

Quick Facts

Height

9 ft

Light

Full Sun to Part Shade

Hardiness

Zone Zones 3a–8b

Fall Color

Red

Origin

stony slopes

Diseases (5)

Cytospora canker Cytospora Canker Erwinia amylovora Fire Blight Symptom category — not a single disease Leaf Spot Neonectria ditissima Nectria Canker Thekopsora minima and Naohidemyces vaccinii Rust

Pests (10)

Aphidoidea Aphid Choreutis pariana Apple-and-thorn skeletonizer Ash borer Enarmonia formosana Cherry bark tortrix Leaf blister mite Pristiphora geniculata Mountain ash sawfly Pear sawfly (pear slug) Phytoptus pyri Pearleaf blister mite Otiorhynchus spp. Root weevil Malacosoma spp. Tent caterpillar