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thinleaf alder
Alnus incana ssp. tenuifolia


Fort Collins

Synonyms
Alnus tenuifolia
Dimensions
Height: 15.0 ft. to 40.0 ft.
Spread: 15.0 ft. to 20.0 ft.
Growth Form
Shrub, Tree
Program Association
Nature in the City
Wildlife Uses
Amphibians/Reptiles, Fish, Large Mammals, Medium-Sized Mammals, Pollinators/ Invertebrates, Riparian Birds, Shrubland Birds, Wetland Birds, Woodland Birds
Sun Requirements
Full Sun, Part Sun
Water Requirements
Moderate, High
Plant Community
Foothills, Mountains, Plains
Season of Bloom
April, May, June, July
Flower Color
Brown Shades, Red Shades
Leaf Color
Green Shades
Aggressiveness
Not aggressive
Design Considerations
Winter Interest
Other Considerations
Lifespan, No City Data
Duration
Perennial
Natural Landscape Position
Fort Collins Model
3, 4, 5
Soil Type
Clay, Rocky, Sandy
Pests/Disease Prone
No
Hazards/Toxic
No City Data.

Notes

A small multi stem native alder that is best adapted to moist sites. Nice smooth grey bark and dark green foliage. Can handle some shade and does well against buildings. Tends to be short lived.


This is an important larval food host for many of our native invertebrates.


Flora of North America recognizes two subspecies of A. incana, both native to the United States. Subspecies rugosa is native to the northeastern U.S. and Canada and subspecies tenuifolia is native to the western U.S. including the Fort Collins area.