Green Alder vs Black Walnut - TreeTime.ca

Green Alder vs Black Walnut

Juglans nigra

Alnus alnobetula subsp. crispa

NOT AVAILABLE THIS SEASON - MIGHT RETURN

Black Walnut
Green Alder

The Black Walnut is a slow growing, large, straight-stemmed tree with an open crown. It produces dense, very hard, edible nuts.

Black Walnut has a deeply-furrowed, black bark. Its leaves are about 1 foot long, composed of 15 - 23 slightly stalked leaflets on a moderately stout stock which provide good dappled shade.

Despite being highly valued for its edible nuts and its shade tree aesthetics, it is rare to see this tree on the prairies.

Note: Black Walnut's roots produce a substance named juglone that is toxic to some other plants. Consider this when choosing where you plant a black walnut, as you will not be able to grow tomato, potato, cabbage, eggplant, blueberry, azalea, rhododendron, lilac, red pine and apple in the surrounding area.

Note: Plant this tree once. It will not respond well to transplanting.

Note: Although self-pollinating, planting two trees significantly improves nut production.

A top CO2 absorbing species. Experts think this tree may help climate change more than others.

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.

Black Walnut Quick Facts

Green Alder Quick Facts

Lowest Price: $3.49 - SAVE UP TO 42%
Zone: 3a
Zone: 1a
Height: 14 m (45 ft)
Height: 7 m (23 ft)
Spread: 9 m (30 ft)
Spread: 3 m (10 ft)
Light: partial shade, full sun
Light: any
Moisture: dry, normal
Moisture: any
Growth rate: slow
Growth rate: fast
Life span: long
Life span: short
Suckering: low
Suckering: high


Nuts: corrugated nut with edible meat
Hybrid: no
Hybrid: no
Catkins: no
Catkins: yes


In row spacing: 0.9 m (3 ft)
Between row spacing: 5 m (16 ft)
Native to: ON
Native to: AB, SK, MB, ON, NS, NB, NL, YT
Other Names: american walnut
Other Names: american green alder