Image for Sitka Mountain Ash

Sitka Mountain Ash

Scientific name

Sorbus sitchensis


Sitka Mountain Ash is a small deciduous tree or shrub species that typically grows up to 6 m in height. This plant may also be known by the common names Western Mountain Ash, Pacific Mountain Ash, or Rowan. The bark is smooth, thin, and gray colored. The leaves are alternately arranged, compound with 9-11 leaflets, shiny, blueish green colored, and have serrated margins. The flowers are creamy white colored, appear in large clusters of 15-60, and bloom between June and July. These flowers become small bright red fruits, which remain throughout the winter. The flowers are beneficial to pollinator species, such as bees and butterflies. The fruits are beneficial to wildlife species, such as birds and small mammals. This tree can grow as either an ornamental tree or a hedge-like shrub, depending on pruning. The roots are good for controlling erosion and stabilizing shorelines. This plant has often been chosen for streambank rehabilitation.

Planting conditions

Sitka Mountain Ash grows best in dry to moist conditions with full sun exposure. It prefers well-drained sand or loam soil types. It can tolerate drought and dry soil but young plants should be watered occasionally during hot summers. It also tolerates steep slopes and nitrogen poor soil. It is intolerant of shade. This plant can be naturally found in open forests, around forest edges, on steep slopes, and along stream or lake shorelines.


  • Plant height:
    • Any
    • Over 3m
  • Moisture level:
    • Dry
    • Normal
    • Moist
    • Drought Tolerant
  • Light conditions:
    • Full sun
  • Soil type:
    • Sandy
    • Loamy
  • pH:
    • Normal
  • Depth:
    • Potted
  • Eco Zone:
    • 2a
    • 2b
    • 3a
    • 3b
    • 4a
    • 4b
    • 5a
    • 5b
    • 6a
    • 6b
  • Plant type:
    • Tree
  • Height:
    • 6 m
  • Spread:
    • 3 m