Western Mountain Ash vs Sitka Alder - TreeTime.ca

Western Mountain Ash vs Sitka Alder

Alnus alnobetula subsp. sinuata

Sorbus scopulina

CUSTOM GROW

NOT AVAILABLE THIS SEASON - MIGHT RETURN

Sitka Alder
Western Mountain Ash

Sitka Alder is a native deciduous shrub or small tree that often forms dense thickets. Its extensive root system stabilizes slopes and streambanks. Nitrogen-fixing capabilities and nutrient-rich leaf litter improve soil fertility, creating better growing conditions for surrounding plants. These qualities make it especially effective in disturbed or erosion-prone sites.

Often found in moist, high-elevation mountain environments, Sitka Alder also enhances habitat by providing cover and structure in both riparian and upland areas. Birds and small mammals utilize it for nesting, and its seeds serve as a food source.

Note: We use Sitka Alder for Alnus alnobetula subsp. sinuata. This species is also known by many other common names, including Mountain Alder, Green Alder, and others. Please confirm the scientific name to ensure you are ordering the correct plant.

Western Mountain Ash is a popular ornamental tree native to the western part of North America. Its attractive, white clusters of flowers bloom in early summer, making way for red, yellow or orange fruit in the fall. If the fruit doesn't catch your eye, Western Mountain Ash's autumn colours will capture your–and the birds's–attention.

Sitka Alder Quick Facts

Western Mountain Ash Quick Facts

Zone: 2a
Zone: 2a
Height: 5 m (15 ft)
Height: 9 m (30 ft)
Spread: 3 m (10 ft)
Spread: 6 m (20 ft)
Light: partial shade, full sun
Light: full sun
Moisture: wet
Moisture: dry, normal
Growth rate: medium
Growth rate: medium
Life span: medium
Life span: medium
Growth form: upright to prostrate, thicket-forming
Spreading: seed - medium, layering - medium
Suckering: none


Bark: redish-brown to grey, smooth
Flowers: white
Berries: bunches of orange-red berries appear in late summer
Hybrid: no
Hybrid: no
Catkins: yes
Catkins: no


Native to: AB, BC, YT, NT
Native to: AB, BC, SK, MB, YT, NT
Other Names: wavy leaf alder
Other Names: cascade mountain ash, greene mountain ash