SelecTree: Tree Detail
Photo Locations: Mendocino Coast Botanical Gardens - Fort Bragg, CA
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.
Erect or Spreading and requires ample growing space.
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.
Special Uses & Values
Cite this tree:
SelecTree. "Alnus rubra Tree Record." 1995-2020. Feb 27, 2020.
< https://selectree.calpoly.edu/tree-detail/alnus-rubra >