The Mexican fan palm, or Washingtonia robustica, is native to the northern Mexico regions of Baja California and Sonora. The plant’s short and shallow roots make it dependent on an abundant water source. In Mexico, these palm trees grow in desert oases. Though the Mexican fan palm is found infrequently in its indigenous desert habitat, it planted generously over the southwestern United States. These skydusters are recognizable as the signature palm over the Los Angeles skyline.
Like all palms, the leaves on the Mexican fan palm are evergreen. They are broad, fan-shaped and spaced alternately on the crown of the plant. The old fronds do not fall to the ground when they die, so a skirt of brown thatch will hang below the new green fronds. The palm produces patches of large white flowers that fall below thatch line.
The Mexican fan palm has a gray trunk that bulges at the base and narrows at the crown. The palm can grow 6 feet (1.8 m) per year and can reach 100 feet (30.5 m) in height. These palms can live to be 150 to 200 years old.
This plant is fast-growing, so the Mexican palm can give instant satisfaction when planted in home gardens. It can be purchased as a small baby plant or as a larger, older plant. The Mexican fan palm also can be grown by seeds purchased from a reputable dealer.
Mexican fan palms grow best in a hot, dry climate. They can tolerate droughts and poor soil but grow best when planted in a sandy, well-draining soil and given adequate watering. Mexican fan palms are hardy plants in the cold, but they will die if temperatures are below freezing for more than a day.
Mexican fan palms are susceptible to root rot, and gardeners should take care not to over-water palms in cool weather or allow mulch to rest near the tree trunk. Palm trees should be fertilized in early spring and summer with a slow-releasing fertilizer made for palms. Pests such as rats, lizards, wasps and other insects make homes in dead thatch on the tree.
A professional should remove brown fronds regularly. Without maintenance, thatch eventually will fall off tall trees by itself. Self-pruning should be avoided unless the owner is aware of proper techniques, because pruning palms in an incorrect manner could harm the tree permanently.