someone I know, from whom I got a fairly decent maple bonsai, recommended burying trees into a raised garden bed, for the winter. This would seem to make sense, the raised beds won't freeze as redily, and the fact that the trees are lower than the top of the raised bed, it would protect them from wind. The one's I have are being used for tomato plants, now and the only issue I could think about would be a lot of sun. Do any of you have experience with such things? or any ideas?