Southern California Walnut

Juglans californica

Native to:
United States

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Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Juglandaceae
Genus:
Juglans
Species:
Juglans californica
USDA Symbol:
JUCA

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Shrub , Tree
Height:
900 cm
Light Requirements:
Part Shade
Drought Tolerance:
High
Bloom Months:
mar,apr,may

Wildlife Benefits

Caterpillars:
★☆☆☆☆ Recorded caterpillar host plant (HOSTS Database)

Keystone Species Ranking

Caterpillar Keystone:
★★★★★ Butterfly & moth species supported by this genus (NWF)

Host Plant for Caterpillars

Fall webworm (Hyphantria cunea), Leconte's haploa (Haploa lecontei), Semiothisa aspirata, Spilosoma vestalis, Western tussock moth (Orgyia vetusta)

Reported Fauna Sightings

Moths:Stigmella longisacca

Garden & Ecology Notes

Wildlife Value:
birds, squirrels, small mammals
Deer Resistant:
Yes
Fall Color:
yellow
Fire Ecology:
Fire adapted — tolerates or benefits from fire
Fire Notes:
Resprouts vigorously from the root crown following fire; multi-stemmed growth form often results from past fire events.

Soil Requirements

Soil Type:
well-drained, sandy loam soil
pH:
6.0 - 7.5 (slightly acidic to neutral)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
prefers alluvial soils in native habitat

Propagation & Germination

Stratification:
Cold/moist stratification required — 90–120 days
Germination Time:
30–60 days
Notes:
Seeds require cold stratification; plant nuts 2-3 inches deep in fall for natural stratification or refrigerate in moist medium.

The above propagation data sourced from Claude AI

Pre-treatment: Cold-moist stratification for 30 days at 1–5°C (34–41°F).; then Cold-moist stratification for 90 days.

Source: Claude AI