SelecTree: Tree Detail
SOUTHERN CALIFORNIA BLACK WALNUT
Photo Locations: Rancho Santa Ana Botanic Gardens - Claremont, CA and San Diego Botanic Garden - Encinitas, CA
Resistant to oak root fungus. Usually has multiple main trunks from ground level. Smaller than its northern counterpart.
Has Unpleasant fragrance.
Native to Southern California.
A Juglans californica in Chico is registered as a California Big Tree. It measures 112 feet high, with a trunk circumference of 259 inches and a crown spread of 106 feet.
Additional Common Names
CALIFORNIA BLACK WALNUT, SOUTHERN CALIFORNIA WALNUT
Erect or Spreading and requires ample growing space.
Has Deciduous foliage.
Height: 15 - 30 feet.
Width: 15 - 30 feet.
Growth Rate: 24 Inches per Year.
Longevity 50 to 150 years.
Leaves Pinnately Compound Odd, Green, Golden or Yellow or Orange, Deciduous.
Flowers Inconspicuous. Flowers in Spring. Has separate male and female reproductive parts on the same tree (monoecious).
Prolific, Brown or Mostly Green Nut, Large (1.50 - 3.00 inches), fruiting in Fall Edible.
Bark Dark Brown or Dark Gray, Furrowed or Smooth.
Shading Capacity Rated as Moderately Dense in Leaf.
Shading Capacity Rated as Moderately Low out of Leaf.
Litter Issue is Dry Fruit.
Tree Site Conditions & Constraints
Sunset Zones 18 - 24.
USDA Hardiness Zones 8 - 9.
Exposure Full Sun to Partial Shade.
Moist to Dry Soil.
Loam or Sand Texture.
Highly Acidic to Slightly Alkaline Soil pH.
Seaside Tolerance is Good in Mild Zone.
Pests & Disease Information
Resistant to Armillaria and Verticillium. Susceptible to Aphids and Caterpillars, Mistletoe, Phytophthora, Root Rot and Sooty Mold.
Health, Safety & Environmental Concerns
Branch Strength Rated as Medium.
Root Damage Potential Rated as Moderate.
Allergy Health Hazard.
Biogenic Emissions considered Moderate.
Desirable Wildlife Plant.
Attracts Birds and Squirrels.
Special Uses & Values
Cite this tree:
SelecTree. "Juglans californica Tree Record." 1995-2021. May 13, 2021.
< https://selectree.calpoly.edu/tree-detail/juglans-californica >