The Southern California Walnut is a large deciduous shrub or tree native to coastal regions of California. It can reach heights of 20-40 feet with branches spreading to 25 feet wide. The leaves turn bright yellow in fall and small flowers bloom from April to May. Edible nuts ripen in August and provide a food source for birds and squirrels. This drought tolerant plant thrives in full sun to part shade and requires little care once established, making it a good choice for larger gardens, hillsides, and providing habitat for wildlife.

1. Southern California Walnut – Juglans californica
(JUG-lans ka-li-FOR-ni-ka)
nut in hull
Family: Juglandaceae (Walnut Family)
Native to: Coastal regions and coastal ranges of CA from central coast to San Diego Co.; is locally
dominant in the coast live oak areas of S. oak woodland; occasional isolated stands in chaparral,
coastal sage scrub and even grasslands. Often on slopes, or in canyons, valleys, riparian areas.
Growth characteristics: woody tree/ lg. shrub mature height: 20-40 ft.
mature width: to 25 ft.
Large deciduous shrub or tree. Often multi-trunked but may form a rounded tree shape.
Bark
gray-brown & furrowed with age. Leaves turn bright yellow in fall. Nuts are edible and husks are
used for natural black dye. Wood is used for woodworking. Lifespan: 100 years.
Blooms Apr-May. Flowers small, clustered on drooping branches. Male and female
flowers on same plant (monoecious) and wind pollinated (self-fertile). Nuts ripen in August.
Blooms/fruits:
Uses in the garden: Most appropriate for larger gardens, hillsides, canyons. One our best trees for
bird & animal habitat. Excellent shade tree. Attractive foliage.
due to chemicals released from leaves (allelopathy).
Difficult to grow plants beneath it
Sensible substitute for: Non-native medium-sized trees including Eucalyptus, Liquidamber
Attracts: Excellent bird habitat: provides cover, perching and nesting sites, and seeds for food
(jays, pigeons, doves). Squirrels love the nuts.
Flowers attract insects, butterflies.
Requirements:
Element
Sun
Soil
Water
Fertilizer
Other
Requirement
Full sun (more tree-like) to part-shade (more shrub-like)
Does well in clays, but ok with any texture; any local pH
Low needs; best with no summer water
None required
Not much required.
and ground squirrel predation.
Management:
If needed, prune only when dormant (fall). Subject to gopher
Propagation: from seed:
best from fresh seed in fall. Plant either in deep pots or in prepared
garden site. Seeds may benefit from 1-2 min hot water soak. Plant out seedlings while small
by
cuttings: not usually done
Plant/seed sources (see list for source numbers): 1, 7, 12, 13, 14
1/2/13
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