One of the most recognizable palms on the planet would have to be Washingtonia palms. These palms are found all over the southwest United States, Mexico, Baja, Texas and Florida.
They are very easy to grow, cold hardy to zone 8+ and can adapt to many soil conditions. Washingtonia palms can be kept small in a pot or can be grown in the ground where the Washingtonia Robusta can reach up to 100 feet in height!
What Are They?
The Washingtonia genus consists of two species; the Robusta (Mexican Fan Palm) and the Filifera (California Fan Palm). While similar in many ways, there are some noticeable differences between the two. Here are some key features of the Washingtonia Robusta vs Filifera.
Robusta (Mexican Fan Palm)
- Taller and more slender trunk.
- Fronds have a shiny appearance with a deep green color.
- Not as cold hardy as the Filifera
- More moisture tolerant.
Filifera (California Fan Palm)
- Shorter, thicker trunk
- Fronds are more deeply divided and have more of a dull, grayish appearance
- More cold hardy than the Robusta
- Prefers drier, more arid climates
Where Will They Grow?
Washingtonia palms are quite adaptable to many soil and environmental conditions. These palms are so easy to grow that they’ve become an invasive species in certain areas of the U.S. given that they are in their ideal growing climate.
When it comes to cold tolerance, these two have moderate differences.
The Filifera is more of a dry climate lover than the Robusta and will take temperatures about 8 degrees F lower than the Robusta. It is hardy down to zone 8a in dry winter climates, but can have trouble surviving wetter winter climates in these same temperatures.
The Robusta on the other hand does thrive better in areas with more moisture, but isn’t as cold tolerant as the Filifera. They tend to do best long term in zone 8b and above in the more southern areas of the U.S., such as Texas, Arizona and Nevada where the cold snaps are shorter and the summers are hotter.
Washingtonia “Filibusta” Hybrid
Since some of the differences in the two Washingtonia species can be minor, you will still find the Robusta and Filifera growing in many areas together. This has caused a common hybrid offspring of the two known as the “Filibusta”.
This Washingtonia hybrid has an appearance that takes on elements of both species, usually with a thicker trunk than the Robusta and deeper green fronds than the Filifera. These palms can also have varying degrees of the hybrid appearance with some looking more like the Robusta or more like the Filifera.
This hybrid species also combines the cold tolerance of the Filifera with the moisture tolerance of the Robusta to create an even more versatile type of Washingtonia palm.
The Filibusta is a great species to experiment with in colder, wetter areas such as lower elevations and coastal regions of places like Oregon and Washington in the U.S. and colder, zone 8 areas of Europe where the Filifera and Robusta may not thrive as well on their own.
Who Are They For?
Washingtonia palms are great if you are looking for something affordable, fast growing, tropical looking and low maintenance.
They are perfect for planting around swimming pools, decks, along driveways and entryways or to give your yard that classic “California” look, if that’s what you’re going for.
Don’t have a yard to plant them in? No problem! These palms can be kept in pots for years, so if you live in an apartment, condo or just aren’t ready to plant it in the ground just yet, they will do just fine in a pot with lots of light and occasional watering.
I actually have a 22-year old Robusta that’s been growing since a seedling in a pot I’ve been hauling around for years. It’s never been fertilized, seen little to no direct sunlight (in some cases for several weeks at a time) and it’s still going strong! One day, hopefully in the near future, I’ll plant it in it’s permanent home.
As mentioned before, these palms are very easy to grow and in their ideal climates, they can get quite “weedy”. They will drop thousands of seeds each year, so maintaining and cleaning up the seeds of these palms is very important so you don’t get an infestation of seedlings taking over in the spring.
A nice, but possibly negative feature of this palm (depending on your preference) is the petticoat of dead fronds that form under the crown. This is such a prominent feature of the Washingtonia that they are also referenced as the “petticoat palm”.
While this look is unique and can be visually appealing, the collection of dry, dead fronds can harbor areas for pests such as rats, snakes and other vermin to thrive.
In really dry areas, the petticoat shag of the Washingtonia can also be a fire hazard, since some of these fronds have been attached to the tree for years, creating a potentially dangerous situation around high heat or open flames.
Regular trimming of dead fronds over time will ensure these problems will be kept at bay, especially when these palms are planted near structures.
The Wrap Up
If you are just starting your research into the ideal palm for your yard and need something that is low maintenance, fast growing and visually appealing, both of these Washingtonia palms, along with the hybrid species, are an excellent choice to start with. They are also a very affordable palm as well, since they are so easy to maintain and start from seed.
While both species can withstand a variety of climate types, keep in mind that the Washingtonia Filifera will look it’s best in drier, desert climates while the Robusta will look and thrive best in mild coastal and Mediterranean climates.
For even more versatility, the “Filibusta” hybrid is a great choice as well since it combines the cold tolerance of the Filifera and the moisture tolerance of the Robusta making it a great option for many borderline growing zones.
As you can see, you really don’t have to choose just one or the other in most cases, but knowing the minor differences between these species can give you an advantage of knowing what conditions your palm will need to look it’s best.