Ninebark vs Mountain Alder - TreeTime.ca

Ninebark vs Mountain Alder

Physocarpus opulifolius

Alnus incana subsp. tenuifolia

CUSTOM GROW

CUSTOM GROW

Ninebark
Mountain Alder

Ninebark is a small, multi-stemmed shrub, that is used to add texture or colour to any yard.

It features flaky, cinnamon-brown bark, attractive white flowers, and long, maple-like leaves.

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.

Ninebark Quick Facts

Mountain Alder Quick Facts

Zone: 2a
Zone: 1a
Height: 2.1 m (7 ft)
Height: 6 m (20 ft)
Spread: 2.1 m (7 ft)
Spread: 3 m (10 ft)
Light: full sun
Light: partial shade, full sun
Moisture: dry, normal
Moisture: normal, wet
Growth rate: slow
Growth rate: medium
Life span: long
Life span: medium
Growth form: multi-stemmed, thicket-forming
Spreading: rhizomes - medium, seeds - low, layering - low
Suckering: none


Bark: smooth, gray to brown
Flowers: small white clusters
Berries: small pink to purple berry like follicles
Hybrid: no
Hybrid: no
Catkins: no
Catkins: yes


Native to: ON, QC, NS, NB
Native to: AB, BC, SK, YT, NT
Other Names: river alder, speckled alder, thin-leaved alder, thinleaf alder, western river alder