Filifera is cold hardier and prefers drier conditions. Robusta is faster growing, somewhat more tender but faster in recuperating from non-lethal cold damage. Filiferas prefer a drier atmosphere, while robustas can handle humidity better. Personally, I prefer robustas. Both are easy from seed. Keep in mind these two HYBRIDIZE readily and many 'filibusta' are also around!

Filiferas are definitely more cold tolerant. I also like the look of robustas better, but Robustas fry at 20F and Filiferas hang on until about 15F. They need dry weather. Since they are seen in Houston and many other humid parts of Texas, my guess is Filiferas can handle summer humidity, but they dont grow very abundantly in much of the southeast and Florida because its too moist!
Robustas are nicer looking in my opinion and more willing to survive on the east coast. Filiferas are shorter, fatter, and more cold tolerant than robustas and they need dry conditions to survive. In good conditions, they are both very fast growing, but Robustas are probably a bit faster.
Good luck!
-Alex

Thank you very much for your advice. Now to find a nursery that sells these buggers. I may be taking a road trip to Virginia Beach, so I hope either walmart or home depot or lowes has them down there. Thanks again. If I had the choice to pick from the two I
M thinking of going with robusta. New York City weather is definatley moist and higher in humidity than parts of Texas. I will sacrifice the five degree difference in hardiness.

Hardypalmfreak- there are no pm's on here... so if you are coming to virginia beach let me know when i would love to show you around and i can get you any size super hardy robustas. I def. prefer Robustas in every way on the east coast but the cali fan is def more cold tolerant! -Justin in VB

Thank you - I will let you know

The last winter 2010/11 the lowest temp for one night only we had was 16-17F and this winter 2011/12 so far we had the lowest 22F or even as low as 21F (warm winter for a zone 8, which is close to 7B by the old standards) so my 12-15 ft. tall Washingtonia robustas turned "khaki" colour, something between green and brown, but the fronds did not break, are still standing up right. I also have a small (3 ft. overall height) Phoenix sylvestris that did not get any damage apart from the slight "khakiness" (turning khaki a little bit). All other temps were 28F and above and I noticed that 28F and maybe as ow as 25F keeps palms absolutely green, so I assume that all palm trees in a zone 9B and higher remain green all winter. I had a bunch of Washingtonia filibusta hybrids about 1 ft. tall in pots that stayed outside at 22F and did not get any damage apart from turning slightly "khaki" on some fronds. The needle palm (hardy to at least Z7) in pot remains completely green and unaffected by 22F. It looks like the smaller the palm the less damage it receives from such temps even if it is in a pot as opposed growing in the soil as a large palm (South Carolina Midlands, zone 8A/8B)

Not all palm trees can survive z9b freezes. There even some palms that die below 50f! Many palms can take z9b winters just fine with no damage at all, like the ones above. But we too have problems with palms dying or getting frost bite. It depends on the type of palms and your climate etc. i also tend to like Robusta, their thinner trunks look alot nicer when they get tall! The only problem with both these palms is they grow like weeds!!!

- US_Marine

The situation with Washys is that,even if you try to buy a specific
one,you are more than likely going to end up with Filibusta.

Probably for the best really.......little of the best of both(-:

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