WSU Clark County Extension

PNW Plants Searchable, categorized images

Mountain Ash

Scientific name: Sorbus aucuparia Cardinal Royal

Type:Deciduous tree
Plant Requirements
Zone:2 to 6
Plant Characteristics
Height:35 ft
Width:20 ft
Bloom Time:May to June
Bloom Color:White
Additional Characteristics



Wildlife value

Description As a native to Europe and Asia, European mountain ash has now been widely planted in northern North America as an ornamental. It is primarily cultivated for its compound green leaves and attractive clusters of fall fruit.

The cultivar 'Cardinal Royal' has been selected for its brilliant red berries, as oppossed to the more typical orange of the species.

As a small deciduous tree, mountain ash grows 20-40’ tall with a narrow, upright-oval crown, usually rounding and opening with age. It bears compound, odd-pinnate, flat medium green leaves which have 9-15 serrate, oblong-lanceolate leaflets (each leaflet being 2.5” long). In May small, white, 5-petaled flowers (1/3” across) appear on flattened corymbs. Later in the summer these flower clusters give rise to pendant clusters of orange-red berry-like drupes, which are readily consumed by song birds. In the fall leaves turn yellow to a very striking reddish-purple.

Best grown in moist, acidic, well-drained soils in full sun. It does best in cool mountain climates.

Bacterial fireblight can be an occasional problem in areas west of the Cascades. Nectria canker can also occur, but with only limited frequency. Both problems can be avoided by planting mountain ash in areas of good air circulation.
For assistance, contact Dr. Charles Brun (, (360) 397-6060 5701
Computing and Web Resources, PO Box 6234, Washington State University, Pullman WA 99164-6234