Combo Plum Tree: What could explain this?
I have a 5-year-old combo plum with three varieties. This spring it leafed out fully and blossomed well, and then about 6-8 weeks ago, as the blossoms started to wilt, I also lost about 2/3 of the leaves on one side of the tree. One part of the tree stayed fully green and the other side was bare branches. I thought maybe it was on its last legs and considered removing it. However, I noticed that the bare branches all had lots of fruit forming. Several weeks later, the branches are re-leafing and the fruit continues to grow in size. At the time of the leaf drop, the temperatures were cool, but above freezing. Anyone care to guess what caused this? Here is a picture of the recovering tree: