Black Locust vs Sitka Alder - TreeTime.ca

Black Locust vs Sitka Alder

Alnus alnobetula subsp. sinuata

Robinia pseudoacacia

CUSTOM GROW

NOT AVAILABLE THIS SEASON - MIGHT RETURN

Sitka Alder
Black Locust

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.

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.

Sitka Alder Quick Facts

Black Locust Quick Facts

Zone: 2a
Zone: 3a
Height: 5 m (15 ft)
Height: 12 m (40 ft)
Spread: 3 m (10 ft)
Spread: 8 m (25 ft)
Light: partial shade, full sun
Light: full sun
Moisture: wet
Moisture: dry, normal
Growth rate: medium
Growth rate: fast
Life span: medium
Life span: long
Growth form: upright to prostrate, thicket-forming
Spreading: seed - medium, layering - medium
Suckering: high


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


Native to: AB, BC, YT, NT
Other Names: wavy leaf alder
Other Names: false acacia, yellow locust