SelecTree: Tree Detail

RED ALDER
Alnus rubra

Alnus rubra Alnus rubra Alnus rubra Alnus rubra Alnus rubra Alnus rubra Alnus rubra Alnus rubra Alnus rubra Alnus rubra Alnus rubra Alnus rubra Alnus rubra Alnus rubra Alnus rubra

Photo Locations: Mendocino Coast Botanical Gardens - Fort Bragg, CA

General Notes

Rarely found more than 10 miles from coast in California. Useful where underground water is somewhat saline.

Native to Western North America.

An Alnus rubra in Golden Gate National Recreation Area is registered as a California Big Tree. It measures 87 feet high, with a trunk circumference of 228 inches and a crown spread of 100 feet.

Family: Betulaceae

Synonyms

Alnus oregana

Tree Characteristics

Erect or Spreading and requires ample growing space.

Conical Shape.

Has Deciduous foliage.

Height: 80 feet.

Width: 30 feet.

Growth Rate: 36 Inches per Year.

Longevity 40 to 150 years.

Leaves Ovate, Dark Green, Bronze or No Change, Deciduous.

Flowers Inconspicuous. Chartreuse or Yellow. Flowers in Spring. Has separate male and female flowers on the same tree (monoecious).

Prolific, Brown or Orange Cone, Medium (0.50 - 1.50 inches), fruiting in Summer or Fall.

Bark Light Gray or Red Brown, Smooth.

Shading Capacity Rated as Moderate to Dense in Leaf.

Shading Capacity Rated as Dense out of Leaf.

Litter Issue is Dry Fruit.

Tree Site Conditions & Constraints

Sunset Zones 3 - 7 and 14 - 17.

USDA Hardiness Zones 6 - 8.

Exposure Full Sun to Full Shade.

Wet to Moist Soil.

Clay, Loam or Sand Texture.

Highly Acidic to Neutral Soil pH.

Seaside Tolerance is Good in Mild Zone and Medium in Moderate Zone.

Pests & Disease Information

Susceptible to Caterpillars, Powdery Mildew.

Health, Safety & Environmental Concerns

Branch Strength Rated as Medium Weak

Root Damage Potential Rated as High.

Allergy Health Hazard.

Desirable Wildlife Plant.

Attracts Birds.

Deer Palatable.

Special Uses & Values

Riparian.

Cite this tree:
SelecTree. "Alnus rubra Tree Record." 1995-2018. Jun 23, 2018.
< https://selectree.calpoly.edu/tree-detail/alnus-rubra >

This tree is not part of the SelecTree Nursery Connection. If you would like to see this tree listed, or know of a nursery that sells it, please contact us at ufei@calpoly.edu.