For a few years, during the drought, my established Redbud tree has leaves that are smaller and more pale than usual. Squirrels had torn off a considerable amount of bark (I saw them do it!) before this happened. There also are indented dark,long vertical areas on the trunk (canker?). I watered during the drought but not heavily. In spite of all this, the tree is slowly blooming this year.

Would giving the tree some fertilizer help it?

Thanks