PlantFiles: California Fan Palm
Washingtonia filifera

I live in Chicago, and have had this Palm for 15 years, and of course, bring it in the house in the winter.(Gets -10 to- 15F here!) It's been repotted 3 times over the years, but it really is only about 7 feet tall, and about as wide even after 15 years.We use a dolly to move the pot! Usually it has 6 to 7 large fans in the summer. I noticed that the leaf tips get brown when it's out in the summer. I have read that our rain is acidic, and this could be the problem. But I wonder if I over water the palm. Overall, the palm looks very healthy, and people often comment about it. Can anyone comment about over watering, or the acid problem. Thanks

This is a very commonly grown palm in California, from the coast to far inland. It is native to the more inland areas, and the more inland it is grown, the better it tends to look. Those palms grown on the coast, where they get a lot more moisture than they should, often have pinched trunks and very small, sad looking crowns. Those growing in the desert have huge, beautiful crowns and nice, thick trunks.

Commonly confused with the even more common Mexican Fan Palm (Washingtonia robusta), this one can be distinguished by the thicker, nearly always straight trunk-- the crown is also larger and relatively sparser. The leaves a more sea green, as opposed to the deep green of the Mexican fan palm. The petioles are always green--no red or brown in the petioles as there always is in the Mexican palms. It is a slower grower and seems to top out at around 60', while the Mexican palms can get up to 100' tall. Interspecies hybrids are extremely common, however (may even be the most common palms growing in southern California) and tend to have a bit of characteristics of both palms- thick trunks, but full heads and red on the petioles. Some palm researchers consider these two the same species, too.

It is also commonly confused with Brahea edulis, another common avenue palm in southern California. They both tend to have thick, naked trunks and pale green leaves, but the latter has a much denser crown of leaves that have many more pleats to them. Flowers a very different, with the Washingtonia flowers extending noticeably beyond the leaves. The bushier, yellow flowers of the Braheas are shorter than the leaves and tend to be located among the uppermost leaves (Washingtonia flowers stick out in all directions, top to bottom of crown). Seeds of Washingtonia are smaller than peas, while those of Braheas are larger than grapes.

Several of these are doing very well in a park across from my home. Zone 7b. These trees were brought in as huge $1,000 specimens many years ago.

The California Fan Palm is native to the desert canyons of the southernmost part of the state. Palm Springs, the famous desert resort town, derives it name from this tree. Said plant is very invasive here and the stems of the fronds are covered with very sharp, tough, shark-like teeth on both edges. See my image posted elsewhere of a "leaf" from one of many CFP plants that have invaded my garden from next door.