It’s easily mistaken for Washingtonia filifera. Growth is even faster but resistance to frost not as good as its name robusta would suggest.
The trunk is thinner, the corona of leaves less dense and it has more and harder spines along the petiole.
The leaves are fan shaped with less filaments than Washingtonia filifera.
The flowers grow in up to 4 m long stalks.
Grown as a solitary, bordering avenues or as a skyline palm.
Leaves were used for weaving and construction of roofs.
Fruit are edible after boiling.
Mexican Fan Palm, Mexican Washington Palm, Mexican Washingtonia, Thread Palm, Washington Fan Palm, Washingtonia
Washingtonia sonorae, Washingtonia thurstoni, Washingtonia vuylstekeana
Mexico (Baja California, Sonora)
USDA Zone 8, -8 °C
Any soil, well drained
- if the seeds are fresh, don’t bother soaking, if not, soak for 1 or 2 days in lukewarm water
- sow in light soil
- keep at 25-30°C
- germination time: a couple of days if seeds are very fresh, 1 to 3 months otherwise
- repot when the seedlings are big enough to handle, repot in individual pot
- no particular care needed
- drought resistant
- feed during growing season
- as with most palms, growth may be slow the first years but then accelerates
- spines along the petiole are harder and more numerous than with Washingtonia filifera
- both Washingtonia hybridize easily making it difficult to distinguish between them
- Washingtonia are hermaphrodites, a single specimen can produce fruit and viable seed
In my garden:
The seedlings in bigger pots, actually they are soda bottles which I’ve cut in half. I put the upper half back on to form an individual and very cheap mini-greenhouse. This way, you don’t need to water very often. Checking once or twice a week is enough.
Careful: these babies can handle direct sunlight and high temperatures but for most plants you shouldn’t place such devices in direct sunlight as the temperature may get to warm and the plants literally boil. Also, there is a risk of sunburn when condensation water forms drops on the leaves which then act as a magnifying glass.
I didn’t have any problems with Washingtonia filifera and robusta: they are exposed to the south and withstood 30°C this spring and early summer and they grow rapidly, most of them forming their 3rd leaf. They are about 20 cm high now.