Tony

Chinese elm are early to leaf out and trees in pots will warm up quicker the their big brothers in the ground. *If the overnight lows are mostly above freezing then put it outside and only bring it in when you expect a freeze. *If not, your option would be to put it out in the morning and bring it in at night until the weather warms up. You could also keep it in the garage and put a grow light over it.

Tony