Washington palms freeze and die back in the teens, and will not tolerate ground that freezes. They prefer it on the drier side. I would not suggest planting it as I doubt it will survive long. Windmills are a wiser choice. Greg in HOT Tampa Bay

I agree with the last post,I wouldnt try it,anyways they like the desert southwest.

I have grown both robustas and filiferas from seed and as I look around I see all robust (filiferas have died out). I grow them containerized and as indoor/outdoor palms and I believe that the filiferas eventually died out as result of excessive moisture both at the soil and in the air (summers in the East are very humid). Maybe also soil pH?? The robustas look fabulous! This is unfortunate because the filifera is supposded to be more COLD hardy. So, I DO agree that the filifera really prefer a much more arid climate. Having said that, there are things that people in more humid/wet climates can do to help out plants that prefer it drier. For example, with the herbs lavender and rosemary, yucca, and the hardy cacti, I grow them in raised beds (near the house on the south side) with very well-drained soil. Seems to work. Wonder if you might try filifera in a similar type of microclimate. They are usually cheap enough. I just planted two four-feet Trachycarpus fortunei palms grown from seedlings (they're more tolerant of humid conditions) and I will probably do some winter protection (lights, burlap, mulch, etc.), and will also experiment in future years with pindo, Washingtonia, and Sabals (louisiana and texana). PS. I am also in the NYC metro area.

Thanks for your replies. I actually read up on it a little more and saw that it doesn't like humidity.
I guess Ill pass.
I just wanted to add to my collection. I'm currently growing 2 windmills, Butia Yatay, Butia Capitata and a king sago palm and enough bananas that Im going to start giving away the pups soon!
I can tell you the Windmills have been in the ground since last year and this year they have been exploding with growth! Maybe Ill just add another windmill or check out the Robusta.....

-Chip

Well, I would play it very conservatively with the robusta (personally, I would not risk it in the ground in zone 7 when they do so well in containers). If you try in a very protected microclimate, expect the possiblity of loss as part of your experiment. I bet you'd have a better chance with some quicker growing Sabals (louisiana, texana, even palmetto). To mention another arid loving palm, there is Chamaerops (European fan). Bet it would do better than a filifera in our zone. Had one in the ground years ago and it went through a very bad (cold, wet, icy) winter. There was a little die back but it has survived and gotten big again. This is another guy that has gotten too big for container growing as an indoor/outdoor--so it'll be on its own soon (protected locale--south side of house and raised bed). There is also Rhaphidophyllum hysterix but I find they grow very slowly, are prickly(thus needle palm name) and not just don't do anything for me on a purely subjective basis. Good luck! PS. You might also consider the variety of windmills (martianus and wagnerianus are also very hardy and look surprisingly different.

Chip
You can plant a robusta in a pot and winter it in doors
if you just have to have one.

Robusta are more tolerant of water but are less cold hardy. Filifera needs perfect drainage and aeration and the spear must be kept dry.

If you can get the Butias to survive, a Palmetto should do just as well, or better.

Other trunking palms to try:
Trachycarpus Wagnerianus
Sabal sp. Birmingham
Sabal xTexensis

Shrub:
Rhapidophyllum Hystrix
Sabal Minor & Louisiana