Friday, November 28, 2014

Palm trees in San Diego

Fan Palm
The ubiquitous and iconic palm trees that line the streets of towns in southern California are not native. Requiring access to water, they were not widely planted in California until the 20th century.

About 40% of the large ornamental palm trees in the San Diego area of California are Mexican Fan Palms (Washingtonia robusta). The fan palms have large fan-like leaves. The old dead fronds form a skirt that must be cut from the trunk, leaving a rough spiky trunk.

Another 40% are Queen Palms (Syagrus romanzoffiana), native to South America. Queen palms have a soft look due to the droopy leaves. The dead palm fronds trim off completely, leaving a smooth trunk.

Queen Palm
About 10% of large palms in San Diego are Canary Island Date Palms (Phoenix canariensis). The Canary Island date palms have very thick trunks and long, thin, stiff fronds. They are often trimmed so they look like a pineapple. Some of the streets in neighborhoods close to the ocean in San Diego are lined primarily this species.

Canary Island Date Palm
The final 8% or so are King Palms (Archontophoenix cunninghamiana), native to Australia. King Palms look similar to queen palms but have stiff, flat leaves. The dead fronds trim completely, leaving a smooth pale trunk.

King Palm
There are over 2800 species of palm trees, but the 4 species above make up about 98% of all the large palms found in and near the city of San Diego.

Out at Borrego Springs in the desert they grow a lot of edible Date Palms (Phoenix dactylifera). And there is a rare native California Fan Palm (Washingtonia filifera) in some of the nearby desert oases canyons in the Anza-Borrego Desert--the only native palm in California.

Small palms

Not included in the above list of large palms are the Pygmy Date Palms (Phoenix roebelenii), native to Southeast Asia. It is as numerous as all the other palms combined. A cute little palm that barely reaches 7 feet tall is perfect for residential landscaping. They are easy to trim and the seeds aren't as messy as the larger palms--or, rather, the berry-like seeds do not get scattered as widely as the tall palms.

Pygmy Date Palm
Finally, there is the fairly popular Sago Palm (Cycas revoluta), which isn't really a palm at all, but a cycad--an ancient plant form--a gymnosperm related to conifers. Most are smaller, but some reach over 8 feet.

Sago Palm