Image for Western Mountain Ash

Western Mountain Ash

Scientific name

Sorbus scopulina


The Western Mountain Ash is a deciduous shrub species that typically grows about 4 m in height. This plant may also be known by the common names: Cascade Mountain Ash or Greeneā€™s Mountain Ash. The leaves are compound with 9-13 leaflets, yellowish green coloured, sharp pointed, have finely toothed margins, are oblong shaped, and are alternately arranged. The flowers are small, white, appear in flat clusters, and bloom between May and June. These flowers produce small, glossy, reddish orange coloured berries that ripen in the late summer. The berries are edible to humans but should not be consumed in large quantities because it contains hydrogen cyanide. The fruit and flowers of Western Mountain Ash are beneficial to many wildlife species, like birds, as well as pollinator species, like bees and butterflies.

Planting conditions

Western Mountain Ash grows best in moist conditions with full or partial sun exposure. It can grow in a variety of soil types and a range of pH levels. It can tolerate strong winds. This tree may be naturally found in rocky hillsides, meadows, open woods, and along river or stream shorelines.


  • Plant height:
    • Any
    • Over 3m
  • Moisture level:
    • Normal
    • Moist
  • Light conditions:
    • Full sun
  • Soil type:
    • Sandy
    • Loamy
    • Rocky
  • pH:
    • Acidic
    • Basic
    • Normal
  • Depth:
    • Potted
  • Eco Zone:
    • 2b
    • 3a
    • 3b
    • 4a
    • 4b
    • 5a
    • 5b
    • 6a
  • Plant type:
    • Shrub
  • Height:
    • 4 m
  • Spread:
    • 1 m