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Juglans californica S. Watson
California black walnut, Southern California walnut
Synonym(s): Juglans californica var. californica
USDA Symbol: JUCA
USDA Native Status: L48 (N)
Southern California walnut or California black walnut is a multi-stemmed, 20-30 ft., deciduous tree or tall shrub with pinnately compound foliage becoming yellow in fall. Small to medium-sized tree, usually forked near base, with rounded crown.
First found north of Los Angeles in 1850 by the survey of the Mexican Boundary Commission, this species is now established by planting beyond its local range. It is often small and shrublike; in contrast, Northern California Walnut becomes a tall tree with larger nuts to 2 (5 cm) in diameter.
Plant CharacteristicsDuration: Perennial Habit: Tree Fruit: Size Class:
Bloom InformationBloom Time: Mar , Apr , May
DistributionUSA: CA Native Distribution:
from Ventura Co. south, e. to the foothills of the San Bernadino Mts. Native Habitat:
Streambanks, hills & valleys below 2500 ft.
Growing ConditionsLight Requirement:
Part Shade Soil Description:
Poor, mesic soils. Conditions Comments:
Juglans californica can be single-stemmed with training. Juglans hindsii, found near former Indian encampments throughout CA,
is doubtfully distinct from J. californica. J. hindsii is usually single-trunked and up to 50 ft. tall. It is used as a street tree
and as stock for budding English walnuts.
PropagationDescription: Plant nuts in fall or spring. If nuts are sown in spring, they must be stratified.
Seed Collection: Not Available
Seed Treatment: Stratify for 60-120 days at 34-41 degrees.
Commercially Avail: yes
National Wetland Indicator Status
|Status:|| FAC |
This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1
(Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here
for map of regions.
From the National Organizations Directory
According to the species list provided by Affiliate Organizations, this plant is either on display or available from the following:
Santa Barbara Botanic Garden
- Santa Barbara, CA
Record Last Modified: 2007-01-01
Research By: TWC Staff