Washingtonia robusta Mexican Fan Palms & Hybrids. Washingtonia filifera & Hybrid. Filibusta

Washingtonia robusta
Scientific name: Washingtonia robusta
Common name(s): Mexican Fan Palm
Family: Arecacaea
Plant type: palm tree

Flowers/Fruits: In the late spring, the Mexican Fan Palm produces small creamy flowers. Flowers grow in clusters on the branched inflorescence 8-10ft long that extends past the leaves. Flowers are followed by black berry-like drupes, about 1/2 inches in diameter. Fruits are edible, though thin-fleshed. They are sweet and taste like dates, can be dried or made into a jelly.

Growth Rate: Moderate to Fast. Washingtonia robusta is a fast growing palm that can get up to 50–60 ft tall and 5-10ft wide, but usually is not taller than 40ft.

Cold Tolerance: Mexican Fan Palm is cold hardy and can tolerate cold down to 15F but temperature lower than 23F might damage leaves. It is great for growing in USDA Zones 8b (15 to 20 F) to 11 (above 40 F).

The Mexican fan palm is a fast-growing species that can reach heights of 70 to 100 feet, making it too tall for typical residential landscapes. It is native to northern Mexico but grows well in Florida, being hardy down to about 20°F or USDA hardiness zone 9A. This species readily hybridizes with the closely related California fan palm (Washingtonia filifera), a shorter, stockier species that is poorly adapted to Florida’s climate. Mexican fan palms grow well in a wide range of soils in Florida, but do require good drainage. Though considered a desert palm, it is native to areas having permanent surface or subsurface water and thus is not as drought tolerant as might be expected. Mexican fan palm leaves are fan-shaped, about 3 to 5 feet wide, and have sharply toothed petioles about 4 to 6 feet long. Leaf bases are split and reddish-brown in color. Healthy specimens will have full, rounded canopies with at least 30 leaves, but potassium (K) deficiency typically reduces the number of leaves to half or less of that number (Figure 1). They can produce up to 50 leaves per year. In Florida, young Mexican fan palms will retain their old leaves (or old leaf bases if the leaves have been cut off) for a number of years, resulting in a skirt of old dried leaves hanging around the trunk (Figure 2). Once the palms reach about 30 feet in height they typically drop their old leaves or leaf bases within a period of a year or two (Figure 3). Once that occurs these palms essentially become “selfcleaning” and do not require manual removal of old leaves. Trunks of this species are reddish-brown in color, but weather to a light gray over time. They taper from nearly 2 feet in diameter at the base to as little as 8 inches near the top of older specimens. Although palms generally survive hurricanes better than broadleaf trees, Mexican fan palms are more prone to snapping or uprooting during severe storms than other palm species 

Information provided by University of Florida