Hi David, please leave your tree where it is until spring, right before the buds are about to open (not just when they first appear). You won't be able to do anything with it in winter anyhow as it will be asleep (dormant) and not ready to grow, and cutting any part of it may still stimulate mechanics of growth, but if buds do appear and open (before winter) the whole tree could die. Don't grow it indoors ever if you can manage that because it will do so much better outside. Can I ask you why you think it is a Chinese elm (rather than some other kind of elm)? I'm from Quebec and it's really unlikely to be a Chinese one growing wild. If you do dig it up in spring, don't use a terracotta pot, but a wide one only tall enough so that when the tree is in it, the roots reach the bottom, then fill in around them with a good bonsai mix (no potting soil or peat please) of aquarium gravel (you can get nice natural looking brownish ones), perlite and some small bark chips (maybe pine mulch that's been cut up enough so it's not 'shredded' too much, and will allow water to run through it quickly. Also make sure it gets plenty of sun. In another couple of years you could put it in a bonsai pot.

Thanks a lot for your answer. It has the same leaves as a chinese elm. Maybe i'm wrong but from what I saw on Internet it look like it. I want to take it inside instead of outside because I'm worry about how a bonsai in its tiny little pot can survive winter. My appartement has a big large sunny windows. You from Qc city? I'm from Montreal. In

David, a picture would be so helpful, one that shows the leaves fairly closely, but not so much they blur. I'm from Mtl.