Last July a branch about 8-10 inches in diameter broke off our ash tree at the point where it intersected with the vertical branch that is now dead that can be seen in the center of the picture. During the rest of the summer and into the fall I made sure I watered the tree when the rain was sparse in an effort to minimize the stress of losing a large branch. It all seemed fine into the fall and through the winter, but when the tree leafed out this spring, it was obvious the branch adjoining the break was dead along with some other unrelated branches that can be seen to the right. I'm wondering what is going on and what can be done about it. Any help would be great. Thanks