You can plant trees
and bushes clear up until the ground starts freezing and I would imagine by now the ground is frozen, so I don't think you'll get very far! As for putting some trees
in a pot, you could get Spruces and place them in a pot. I would leave any burlap around the rootball for added protection. And I would put some mulch on the top of the soil after you've put it in the pot. Water only sparingly, but they do need water. trees
in the ground and getting their moisture from there-snow, so we tend to forget that things in pots still need to be watered.