California Walnut
Juglans californica
Juglandaceae · broadleaf deciduous tree · introduced
Last updated
Plant Profile
Size & Form
Height
40 ft
Spread
15-30 ft
Growth Rate
Medium
Site Requirements
Light
Full Sun
Soil Drainage
Moist
Soil pH
4.5-8.5
Water
Moderate
Drought Tolerance
Moderate
Hardiness
Zones 8a–8b
Ornamental Interest
Bloom Time
april to may
Fall Color
Brown, yellow
Origin
southern California, approximately from Santa Barbara to
Watch for this season
Fall webwormHigh
Larval Feeding & Web Building
Phytophthora Root RotModerate
Growing Season Stress Expression
Crown GallMonitor
Dormant in Soil
Diseases: Regionally Documented (10)
Geosmithia morbida (vectored by Pityophthorus juglandis) Thousand Cankers Disease Xanthomonas arboricola pv. juglandis Walnut Blight Blackline virus Blackline Ophiognomonia leptostyla (syn. Gnomonia leptostyla) Anthracnose Blotch Black Walnut Toxicity Rhizobium radiobacter (formerly Agrobacterium tumefaciens) Crown Gall Pseudomicrostroma juglandis (syn. Microstroma juglandis) Downy Leaf Spot Mosses and Lichens Phytophthora spp. (P Phytophthora Root Rot Pratylenchus penetrans (primary) and P Nematode, Root-lesion
Pests: Regionally Documented (6)
Data Maturity Structured Multiple sources. Expert review underway.