There is a big difference in the hardiness tolerances of Washingtonia compared to T. fortunei. T. fortunei's are good down to about zone 7a--especially in a good microclimate and if they are big enough. Washingtonia robusta is good down to about zone 8 (8b I think). I've been toying with the idea of Washingtonia in the ground protected (but my growing season is longer than yours and the summers are hotter here). Don't know how well they would recuperate with a shorter and cooler growing seasons when they are essentially in recovery from the winter dieback (even if protected). I would put it into a larger container now as palms gain hardiness with SIZE. Happy gardening!

What zone does your nephew live in? Washingtonias have successfully been overwintered in zones 5 and up maybe even a few zone 4s too, but anything less than a zone 8 and there only chance for survival is great protection. If its really way too large for a pot you can always sell it to someone (up north they go for a lot more than down south).
I would make a decision soon because this time of the year is the best time to plant palms in the ground. Read up on various protection methods, but the larger it gets the harder it is to protect, and unlike a windmill palm, Washingtonias will always need a good amount of protection in a zone 7 for survival.

Good luck!
-Alex

I am in a Zone 8A (Orangeburg county, SC) perhaps ~50 miles south of the old USDA Zone 7B border.

I planted a 8 ft. tall Washingtonia Robusta in August 2009 in a sheltered sunny location on a south side of my house about 2-3 ft. from the wall. It had beautiful foliage, which browned and broke during the winter in December and January. I wrapped it with burlap a lot during the most cold weather for a couple weeks in January. Some time in January there was a unusual snow storm with LOTS of snow which lasted for 2 days although temperatures stayed normal. I was told it will be growing like crazy in May and it did grow a little bit during May (today is 27th of May). It grew a green stem of about 12" inches and another stem of about 5" inches both holding the browned foliage. That is all. Nothing else has come out of it and currently I think it kind f stopped growing, I think.

What is wrong with it? I live in a small town surrounded by forests. Perhaps all the forests and trees cool down and reduce the climate from 8A to a lesser one?

In fact I saw a couple very tall Washingtonias in Columbia, SC area and they were all or partially browned, but seemed doing quite well. One of them I suspect could be a Filifera. It's growing next to some radio station on East side of Columbia.

Also I find European Fan Palm (Chamaerops) not hardy enough for zone 8A since it gets most of the foliage brown during winter where I live, although it does not die and soon recovers some of the foliage. Could this be caused by a rural climate away from cities and from lakes?

Also, I got another 2 robustas which were beautifully green at the nursery, who tied their tops upwith rope in March, yet once planted in my place the foliage became yellow and then brown a lot. Apparently while in the nursery they probably got some freezing weather in March this year 2010 which seems to have damaged the foliage.

So my experience with Washingtonia so far is so-so.

Thanks for all the great advise.... we have decided to re-pot this season and perhaps if it had a major growth spurt this summer and gets stronger and bigger we will attempt to put it in the ground.. although I dont like to take on that kind of responsibility with plants out of our zone (I deal with mostly Jap.Maples and cherrys). Thanks all.

I work in downtown DC. Across the street is a restaurant with an outdoor seating area which they decorate with large potted palms. They never move them after summer and my winters are spent watching these great trees freeze.

One year they had a Washingtonia (hey, were are in Washington...). That sucker took a pounding all winter and almost made it. It finally croaked in early March. If they had just wrapped it, it would probably be alive today.

Thats very interesting!!!! I am wondering if we were to plant it in the ground, maybe next spring... when its larger and stronger and, then, when its ready to be winterized... do it and do it with extra to boot.. if it would make it.

My nephew also has a Windmill which I transplanted into the ground from a large pot.. we winterized it with tarps with holes and lots of leaves... along with stakes and it looked great when we removed it when it was safe to do so..

Maybe we will have luck with the Washy.. never know though.