Sitka Mountain Ash

Sitka mountain ash, also called western mountain ash, is a deciduous small tree native to coastal forests from Alaska to California. Growing 20-40 feet tall, it produces pinnate, finely divided leaves and orange to red berries that persist through fall and into winter.

This species prefers cool, moist climates and well-drained soil in full sun to part shade. Hardy to zones 5-7, it is fast-growing and useful for riparian restoration and native landscapes. The fruit is consumed by birds and wildlife.

Sitka mountain ash is the native alternative to European mountain ash and it handles our climate better. It is adapted to cool, moist coastal conditions and tolerates our wet winters without the heat stress problems that shorten the life of Sorbus aucuparia in the lowlands. Fire blight resistance is better than the European species, though not complete. Five diseases and 12 pests are documented. Mountain ash sawfly can defoliate trees but healthy specimens recover. The orange-red fruit provides excellent winter bird food. For a small native tree in a cool, moist site, Sitka mountain ash is a solid choice. It does not like hot, exposed positions or compacted soils.

— Chris Welch, ISA Certified Arborist