Although sharing fan-shaped leaves and tolerance for hot weather and drought, the Mexican fan palm (Washingtonia robusta) and Texas palm (Sabal mexicana) are not often mistaken for each other. Mexican fan palms soar to 100 feet on slender trunks. Think majestic rows of trees lining Hollywood streets. Their stouter Texas palm cousins spread more, but stop growing at about 50 feet tall. Comparing trunk diameters, a Texas sabal's may span almost 3 feet, while a Mexican fan palm's usually measures 10 to 12 inches.
Climate and Environment
The tallest of the palms, the Mexican fan palm come from the Mexican desert mountain valleys and canyons of the Sonoran Desert and Baja California. Present-day descendants of these trees grown in U.S. Department of Agriculture plant hardiness zones 9 through 11. The only full-size palm native to the Lone Star State, the Texas sabal palm's natural habitat is the rich soil of the Gulf Coast. This palm grows in USDA zones 8 through 11, and may grow in USDA zone 7b. When grown in humid climates, each tree has shown resistance to root rot disease. Though the Texas sabal palm may not be as readily available, the Mexican fan palm reigns as the darling of commercial landscapers in Florida, California and Arizona.
Tree Growth and Seasons
In the slightly acidic to highly alkaline soil it favors, the Mexican fan palm can add more than 36 inches in height each season. Because it has a life expectancy up to 150 years, it will eventually tower over everything near except skyscrapers. A much slower grower, the Texas sabal palm does not begin to emerge until at least 10 years after planting. Though both are evergreen, the palms produce flowers and fruit on a yearly cycle. Inconspicuous white blooms show up on the Mexican fan palm in early summer, then produce black berries. For the Texas sabal palm, fragrant white blossoms appear in spring, and later, dark purple fruits hang in clusters from the branches. The fruit of the Texas palm, in particular, lures birds and other wildlife.
Though it prefers bright sun, the Mexican fan palm can tolerate some shade. A bit more adaptable, Texas sabal palm will flourish in different levels of sun. Leaf color may vary from a deep emerald green when grown in partial to full shade, to a lighter green where it gets more sun. Once established, both palms can exist on infrequent watering, but each looks better and grows faster when given adequate water. In addition, both can withstand the salinity of coastal gardens.
Especially for the Mexican fan palm, the "hula skirt" effect of dead leaves hanging from the trunk presents problems. Though many people consider this an attractive feature of the tree, the dead, dry leaves can be a fire hazard and may provide a home for rats and other unwanted critters. Some California municipalities require removal of these shaggy skirts, but the logistics prove difficult when the offender stands 80 or 100 feet in the air. Probably the main drawback to growing these palms boils down to their size. They might overwhelm a small or medium-sized, yard. While the Texas sabal palm never reaches the Mexican fan palm's height, its canopy may grow to 25 feet across.