Alnus glutinosa 'Imperialis'

Imperial Alder

A distinctive ornamental alder prized for its deeply cut, fern-like foliage that gives the tree a light, elegant texture. More refined than the species, it works well as a specimen tree where its unique leaf form can be appreciated.

Key features



Width: 20–30 ft



Height: 30–40 ft



Foliage: Finely divided, cutleaf, bright green; soft, airy appearance



Form: Upright to broadly pyramidal



Growth rate: Moderate to fast



Life cycle: Deciduous tree



Growing conditions



Sun: Full sun to part shade



Soil: Adaptable; prefers moist to wet soils but tolerates average conditions



Water: Moderate to high; performs well near ponds or low areas



Hardiness: USDA Zones 3–7



Landscape use



Specimen or focal tree



Near water features or rain gardens



Large lawns and naturalized landscapes



Adds fine texture contrast among broad-leaf trees



Notes



As a true alder, it can fix nitrogen, improving soil health



Tolerates poor soils better than many ornamental trees



Best sited with room to spread; not ideal for tight urban spaces

Plant type

Deciduous Tree, Shade Tree, Street Tree

Height

50'

Width

30'

Hardiness zones

4–8

Sunlight

Full Sun, Partial Shade

Growth rate

Slow

Bloom time

Late Spring, Late Winter

Leaf color

Green

Fall color

Green

Attracts

Butterflies

Soil

Clay

Landscape use

Accent Plant, Privacy Screen, Specimen

Shape

Narrow Upright

Bark

Smooth

Fruit

Yes

Fragrant

Yes

Drought tolerant

No