We live in the Chicago suburbs and have two small plum trees that we acquired in the summer of 2016 as very small saplings from a landscaper that specializes in native plants. The trees did not grow at all in the shady front garden where we planted them. This spring we put them in pots in our sunnier back yard and both started growing, one significantly more than the other. We did not manage to get them in the ground by fall and decided to bring them in for the winter with the plan to plant them in our back yard this spring. We put the trees by a window and their leaves immediately turned red and dropped off. Well, I just heard a gardener say on the radio in response to a similar question about someone's decorative tree that it's not good for trees to be inside for the winter because they need a dormancy phase, and that he should just plant it outside now, even though we have had our first frost and first snow (now melted) and temps are in the 30s-40s. But then I found conflicting info on the Internet saying that plum trees and certain other trees should not be planted in late fall or winter. What do you think--should they stay or go outside? We assume that if they should go back outside, they need to get in the ground as they will be too cold in the pots...correct? Thank you!
When to Plant Plum Trees
Certified GKH Gardening Expert
Yes, there does seem to be a lot of conflicting information on this subject. If they are showing signs of coming back to life, then it might be best to leave them inside for their first winter. Usually it is a plum of fruiting age that will not tolerate a lack of dormancy. I'm afraid that if the tree is too young then it will be killed by the cold since it isn't established and won't have time to be. This article will give you information on the care of the trees: https://www.gardeningknowhow.com/edible/fruits/plum/growing-plum-trees.htm
Thanks, BushDoctor, for confirming our instinct to keep the trees inside for the winter. :)