The Californian Palm

There seems to be a lot of misinformation about palms and California – some claim there are no palms native to California, some believe the palms we see all over the state have always been here, and I have even heard the unbelievably-absurd claim from someone who lived in a palm-filled part of California (San Jose) that palms can’t even be grown in California!

Washingtonia filifera in habitat. Photo by Ian Martyn.

This palm, properly known as Washingtonia filifera, is a desert palm that is found naturally only in California, Arizona, and Baja California. This is the tree that Palm Springs is named after and can occur in huge, monotypic stands in oases in the Sonoran and Mojave deserts. This palm is not found growing on the coast, which is perhaps where people got the idea that no palms are native to the state.

The California fan palm is popularly grown in places with arid climates such as southern California and Arizona. It does well in places with more rainfall and warm climates such as Texas, but struggles as rainfall increases. This palm is very tolerant of cold temperatures, but its ability to handle freezes is limited to areas with little rainfall, as cold and wet in combination tend to cause the palm’s heart to rot.

This palm looks similar to its close relative, the Mexican fan palm (Washingtonia robusta), which is found in similar climates in northern Mexico. It is usually less-commonly planted than it’s Mexican cousin, being slower to grow and stouter, as well as being harder to find. This palm’s imposing stature can overwhelm tiny gardens; the tree can grow 60 feet (18 meters) tall and have a crown twenty feet (7 meters) across. The trunk is sturdy and stout, being up to three feet (one meter) thick, grey and often bedecked with a skirt of old leaves when younger. The leaves are costapalmate and are from three to six feet in width. The petioles are armed with sturdy thorns, and the fruit are around a centimeter across, round, and produced by the thousands. The specific name ‘filifera’ describes the many threads that dangle between the leaf segments.

Washingtonia filifera is a popular palm in arid and mediterranean regions; it is often grown in the southwest USA and can be seen on the French Riviera and the Aegean islands in Greece, as well as many other places with similar climates. It takes cold snaps to temperatures as low as 15f (-10c) in dry climates. These palms also do very well in places with extreme heat. This palm can be crossed with the Mexican fan palm, combining their traits of cold-hardiness and better moisture tolerance to produce a cold-hardy, rapidly-growing hybrid called a ‘filibusta’ palm.

The California fan palm is easily grown from seeds and grows relatively rapidly for a desert palm. It transplants well and is relatively easy to obtain. The tree is well-suited to many warm and hot regions of the western US and other similar places around the world. It is a very undemanding plant when grown in a suitable climate, and once established takes care of itself. It is a beautiful addition to suitably-sized gardens and is an excellent choice for xerophytic landscapes.

Palms can obviously be grown in California, and many varieties grow very well here; numerous streets and beaches are lined with sky-dusting palms, and palms are one of the most popular landscape trees found in private and public gardens. There are some palms that grow well even in the cold, fog-shrouded coasts of the far north of the state (and can be easily grown all the way up the coast into British Columbia). In the warm southern and central parts of the state, a couple hundred different taxa of palms survive and thrive, many of which are easily-recognised by casual enthusiasts; the Mexican fan palm is extremely popular and hardy and can grow to great heights – these are likely the tallest palms in California. Canary Island date palms are also popular, their thick trunks and dense crowns of yellow-green leaves and orange fruit make them stand out in the landscape. Queen palms, pygmy date palms, European fan palms, and foxtail palms are among the most commonly grown palms in the western US, as is the only palm native to California (and is the only palm native to the entire western side of the continental divide north of the US/Mexican border): the aptly-named California fan palm.