Terry W

Hokkaido elms are hardy to well below freezing. However, in small pots in your area, they will probably need protection in a cold frame or such. (I grow Hokkaido's in zone 8 so am not qualified to offer much on long term cold weather protection. They overwinter fine on the ground here with leaves around the pots.) I would suggest you do not allow it to stay in soggy soil. Your Hokkaido should be root pruned and repotted in spring when the leaf buds start to swell. Hokkaido's seem to be touchy about root pruning...at least for me. I take off as few roots as possible and avoid prunning larger roots as much as I can. Hokkaido's wood breaks easily. Suggest you wire and bend branches with care.

TerryW