Western Mountain Ash vs Mountain Alder - TreeTime.ca

Western Mountain Ash vs Mountain Alder

Alnus incana subsp. tenuifolia

Sorbus scopulina

CUSTOM GROW

NOT AVAILABLE THIS SEASON - MIGHT RETURN

Mountain Alder
Western Mountain Ash

Mountain Alder is a native cold-hardy shrub or small tree often found along streams and in moist forested habitats. Its nitrogen-fixing ability enriches soils and supports surrounding vegetation, while its extensive root system helps stabilize streambanks and slopes. The fast growth rate allows it to establish quickly on disturbed sites, making it especially valuable in reclamation, restoration, and erosion control projects.

Often forming dense thickets, Mountain Alder enhances habitat quality in riparian and upland areas. It provides food and cover for various wildlife, including birds and small mammals. Recognized as an important species for soil and water conservation, it is well suited for riparian planting, naturalization, and ecological restoration.

Note: We use Sitka Alder for Alnus incana subsp. tenuifolia. This species is also known by many other common names, including Grey Alder, River 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.

Mountain Alder Quick Facts

Western Mountain Ash Quick Facts

Zone: 1a
Zone: 2a
Height: 6 m (20 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: normal, wet
Moisture: dry, normal
Growth rate: medium
Growth rate: medium
Life span: medium
Life span: medium
Growth form: multi-stemmed, thicket-forming
Spreading: rhizomes - medium, seeds - low, layering - low
Suckering: none


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


Native to: AB, BC, SK, YT, NT
Native to: AB, BC, SK, MB, YT, NT
Other Names: river alder, speckled alder, thin-leaved alder, thinleaf alder, western river alder
Other Names: cascade mountain ash, greene mountain ash