Plant Library: California fan palm

This sturdy evergreen resists salt and drought, and will grow well in containers for years.

Left untrimmed, old fronds will form a "petticoat" over the tree's trunk. Phil Schermeister / National Geographic / Getty Images / Gallo Images

Washingtonia filifera, desert fan palm, American cotton palm

Distinguished from Washingtonia robusta by its stouter trunk and the string-like threads that persist on the margins of mature fronds, the California fan palm is an erect, stately, evergreen palm that is native to the southern United States of America.

They can grow 18.3 metres tall with a crown spread of 4.6m. The massive trunk is barrel-shaped and ringed with old leaf scars, and can reach a metre in diameter at its widest point. California fan palm can have up to 30 grey-green fan-shaped leaves, each 1-2m across. They spread out to form a loose and open crown.

If the old fronds are not removed, they form a "petticoat" from the crown that can reach all the way to the ground. The palm produces numerous branching flower clusters that project out and often downwards from the leaf crown. The blossoms are white and yellow and give rise to oblong or round red-black fruit.

The palm has high salt tolerance, good drought resistance and will grow well in containers for some years. Even large specimens will transplant well. Propagation is by seed, which germinates easily, and self-sown seedlings are plentiful.