Green Alder vs Red Alder - TreeTime.ca

Green Alder vs Red Alder

Alnus alnobetula subsp. crispa

Alnus rubra

COMING SOON

CUSTOM GROW

Green Alder
Red Alder

Green Alder is a native, cold-hardy shrub found in boreal forests, along slopes, and in open upland habitats. It fixes nitrogen in the soil, improving fertility and helping other plants grow, while its roots help stabilize slopes and disturbed ground. Fast to establish on poor soils, it is widely used in reclamation, restoration, and erosion control projects.

With its smooth grey bark and shiny green leaves, Green Alder often forms dense thickets that provide cover for birds and small mammals. Its seeds, buds, and catkins also supply food for wildlife. Green Alder is well suited for naturalization and ecological restoration.

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

Red Alder is a fast-growing deciduous tree native to western North America. Through its nitrogen-fixing roots and nitrogen-rich leaf litter, Red Alder improves soil fertility and supports the growth of surrounding plants. This makes it especially valuable on disturbed sites following logging, construction, or fire. A classic pioneer species, it often colonizes bare ground and enhances conditions for longer-lived conifers to follow.

Red Alder stabilizes soils on streambanks and disturbed slopes, reducing erosion and aiding restoration. It also supports wildlife: birds and small mammals eat the seeds and buds, deer and elk browse the foliage, and bees are drawn to the pollen-rich catkins in spring.

Red Alder also has commercial importance, with its strong yet workable wood widely used for furniture, cabinetry, veneer, and pulp. The tree takes its name from the rusty-red color the bark turns when cut or bruised.

Green Alder Quick Facts

Red Alder Quick Facts

Zone: 1a
Zone: 5b
Height: 7 m (23 ft)
Height: 15 m (50 ft)
Spread: 3 m (10 ft)
Spread: 9 m (30 ft)
Light: any
Light: partial shade, full sun
Moisture: any
Moisture: normal, wet
Growth rate: fast
Growth rate: fast
Life span: short
Life span: medium
Growth form: upright, rounded to conical
Spreading: seeds - medium, stump sprouting - medium
Suckering: high


Bark: smooth, grey
Hybrid: no
Hybrid: no
Catkins: yes
Catkins: yes

In row spacing: 0.9 m (3 ft)

Between row spacing: 5 m (16 ft)
Native to: AB, SK, MB, ON, NS, NB, NL, YT
Native to: BC
Other Names: american green alder
Other Names: oregon alder, pacific coast alder, western alder