SelecTree: Tree Detail
CALIFORNIA FAN PALM
Photo Locations: Anza-Borrego State Park, Leaning Pine Arboretum - Cal Poly San Luis Obispo, CA, Stanford University - Palo Alto, CA, Sacramento, CA, Los Angeles County Arboretum - Arcadia, CA, Alameda Plazas and Alice Keck Park Memorial Garden - Santa Barbara, CA
There are currently two species recognized in the genus Washingtonia, though some evidence suggests that Washingtonia is composed of one highly variable species and that local differentiation of populations is related to environmental gradients. The plant material in cultivation can be difficult to distinguish, and all kinds of supposed hybrids exist. In general, the two currently-recognized species can be distinguished, at least at their extremes this way: W. filifera is shorter, with a stouter trunk, more hairlike fibers on the leaf tips, and a less compact crown with longer leaf stalks (petioles) than W. robusta. The California fan palm is native to desert oases and stream courses in southeastern California. Washingtonia filifera has no HPWRA (Hawai'i Pacific Weed Risk Assessment) score.
Native to Southeastern California and Northern Mexico.
A Washingtonia filifera in Capital Park is registered as a California Big Tree. It measures 67 feet high, with a trunk circumference of 141 inches and a crown spread of 18 feet.
Erect and requires ample growing space.
Has Evergreen foliage.
Height: 50 - 70 feet.
Width: 10 - 20 feet.
Growth Rate: 36 Inches per Year.
Longevity 50 to 150 years.
Leaves Palmate, Dark Green, No Change, Evergreen.
Flowers Inconspicuous. . Has perfect flowers (male and female parts in each flower).
Black Drupe, Small (0.25 - 0.50 inches).
Bark Red Brown, Furrowed or Smooth.
Shading Capacity Rated as Dense in Leaf.
Litter Issue is Dry Fruit and Leaves.
Tree Site Conditions & Constraints
Sunset Zones 8, 9, 10 and 11 - 24; H1, H2.
USDA Hardiness Zones 9 - 11.
Exposure Full Sun to Partial Shade.
Moist to Dry Soil.
Loam or Sand Texture.
Slightly Acidic to Highly Alkaline Soil pH.
Salinity Tolerance is Good to Moderate Inland.
Seaside Tolerance is Good in Mild Zone.
Pests & Disease Information
Resistant to Texas Root Rot. Susceptible to Armillaria.
Health, Safety & Environmental Concerns
Branch Strength Rated as Medium Strong.
Root Damage Potential Rated as Moderate.
Allergy Health Hazard.
Biogenic Emissions considered Moderate.
Fire Resistance is Favorable.
Cite this tree:
SelecTree. "Washingtonia filifera Tree Record." 1995-2020. Aug 14, 2020.
< https://selectree.calpoly.edu/tree-detail/washingtonia-filifera >