Black Locust vs Red Alder - TreeTime.ca

Black Locust vs Red Alder

Robinia pseudoacacia

Alnus rubra

COMING SOON

(new stock expected: fall of 2025)

CUSTOM GROW

Black Locust
Red Alder

Black Locust is an attractive tree. Its distinctive leaves are made of about a dozen bright green leaflets. It also notable for its fragrant white flowers, which smell of citrus.

Black Locust can grow in many situations, but prefers dry areas with lots of sun. It is robust and is an excellent choice for establishing shade in dry, open areas.

Important note: Much of the Black Locust is toxic to humans and livestock, including seeds, bark, and leaves.

Red Alder is a fast-growing deciduous tree native to western North America. Its fixes nitrogen, which enriches soils and supports the growth of surrounding plants. Ideal for sites with poor soil conditions, or areas disturbed by logging, construction or fire.
It provides shade in riparian areas, creating cover for fish. Its seeds and buds are eaten by birds and small mammals, while the foliage provides browse for wildlife. The catkins release clouds of pollen attracting bees and other insects.
The Red Alder gets its namesake from the rusty-red color the bark turns when bruised.

Black Locust Quick Facts

Red Alder Quick Facts

Zone: 3a
Zone: 5b
Height: 12 m (40 ft)
Height: 15 m (50 ft)
Spread: 8 m (25 ft)
Spread: 9 m (30 ft)
Light: full sun
Light: partial shade, full sun
Moisture: dry, normal
Moisture: normal, wet
Growth rate: fast
Growth rate: fast
Life span: long
Life span: medium
Growth form: upright, rounded to conical
Spreading: seeds - medium, stump sprouting - medium
Suckering: high


Bark: dark reddish brown to balck with furrows
Bark: smooth, grey
Flowers: Creamy white flowers in a pyramidal shape bloom in may-june
Seeds: dark brown peapod-like pods
Hybrid: no
Hybrid: no
Catkins: no
Catkins: yes


Native to: BC
Other Names: false acacia, yellow locust
Other Names: oregon alder, pacific coast alder, western alder