Washingtonia filifera

The one palm truly native to the American West. Washingtonia filifera, the California fan palm or desert fan palm, is the only palm native to the western United States, gathering in stately groves around desert springs and seeps across the Colorado, Mojave, and Sonoran deserts of California, Arizona, and northwestern Mexico. The genus honors George Washington, and the species name filifera, thread-bearing, names the curling white fibers that hang between the segments of each fan.

Everything about the palm is monumental. A single stout, columnar trunk carries a broad crown of gray-green, fan-shaped leaves five to six feet across, and the old, dead fronds fold down rather than dropping, cloaking the trunk in a russet shag that gardeners call the petticoat or skirt. Left alone the skirt is part of the character; trimmed away, the clean pale trunk stands like a column. Mature palms reach thirty to fifty feet, now and then taller.

For the desert peoples of the Southwest the fan palm was a larder and a workshop. The Cahuilla and neighboring tribes ate the small, sweet, date-like fruit fresh, cooked, or ground into flour, baked the terminal buds, and pounded the seeds into mush, while the long leaves were woven into sandals, baskets, and roof thatch and the stout leaf stalks shaped into cooking tools. Groves marked reliable water in a hard country.

In the garden the California fan palm is a bold, drought- and heat-defying specimen for a large, sunny, well-drained site, hardy through brief cold to the middle teens and reliable in zones 8b to 11. In areas where palms are marginal, give young plants a heavy winter mulch, or pot them on arrival and keep them under cover through the first winter until the trunk begins to build. Give room for the full size, and site well back from walks and drives, since the fronds are large and the leaf stalks toothed.