Palms For California

Pronunciation: wash-ing-TOE-nee-uh fill-LIFF-er-uh

Common Name: California Fan Palm, Petticoat Palm, Cotton Palm

Washingtonia filifera is California's only native palm. Though fairly commonly grown, mature specimens make excellent specimens and still a different look from the overly common Washingtonia robusta (Mexican Fan Palm) which is grown everywhere one looks. These palms do best inland away from ocean influence, which tends to make their crowns sparse and anemic looking. This is an excellent desert palm, which is where they are native to. This species has one of the thickest of all the palm trunks on earth. Hybrids between this and the Mexican Fan Palm are commonly seen in landscapes around southern California.

Appearance and Biology Habit: solitary with a crown of 10-30 leaves Height: 70' Trunk: single; 28" in diameter; usually clean except near top where dense petticoat often present in unpruned mature adult palms; grey-brown in color without any rings; trunks straight up and down, never bending or arching like those of Washingtonia robusta Crownshaft: none Spread: 14'-15' Leaf Description: palmate to mildly costapalmate; divided about half its length; leaflets drooping with age, stiffer when young; leaves a pale to medium green color with a lot of cottony fibers; young palms often have dense cottony fibers along leaflet margins; 9' long Petiole/Leaf bases: all green without the red-brown of the Mexican Fan Palm; heavily armed with large, hooked teeth; leaf bases split but only appreciated in pruned specimens as leaf bases usually covered with dead skirt of leaves, and fall off after several years Reproduction: monoecious and relatively productive for a palm (thousands of seeds below mature seeding palms) Inflorescence: long and arching from middle of leaf bases and eventually hanging down below crown; up to 15' long; white, bisexual flowers Fruit: 1 cm in diameter green to blackish when ripe Seed: 5-6mm diameter, brown and flattened spherical

Horticultural Characteristics Minimum Temp: 15F Drought Tolerance: very good Dry Heat Tolerance: very good Wind Tolerance: good Salt Tolerance: moderate Growth Rate: moderate Soil Preference: well draining and relatively dry but very adaptable Light Requirement: full sun Human Hazards: sharp petiolar teeth; numerous seeds can make sidewalks a bit hazardous Disease or Horticultural Problems: sparse crowns and slightly pinched trunks near coast; some mature palms die suddenly without apparent reasons Transplants?: fairly good Indoor?: poor Availability: common but not always easy to tell if this or the other species when young, and rarely do nurseries identify which is which