Potted Japanese Maples Didn't Make It Through Winter
I collect Japanese Maples in pots. I protected them from the winter by moving them into my garage, the enclosed stairwell leading to the cellar, or with tarps on all 4 sides. Nevertheless, I lost about 25% this winter. A gardener said that they were not as "well rooted" as the survivors. I don't know what that means; they look like they were planted the same to me. It's possible that I waited too long to bring them in last fall, as I had (mistakenly) believed that I should wait until they lost their leaves (which never happened). Do you have any suggestions? For other types of shrubs, I've used some type of root stimulator with mycorrhizal fungi. Thanks for your help. P.S. I can send pictures if that would help, but, as noted, I don't see any differences in how they were planted. .
This was a difficult winter for the survival of Japanese maples planted in the ground so trees planted in containers would have had even a more difficult time surviving. We had a warm fall and as you observed many did not lose their leaves. Then it got extremely cold, dry and windy for prolonged periods. These conditions caused the demise of many container plants this winter that usually overwinter. In a typical winter what you already do sounds sufficient and the fact that 75% survived is a pretty good success rate.