I thought I'd just planted to late... probably contributing factor, tree stressed. Today mulched, bought a slow soaking waterer, and decided to trim the foot of dead growth I thought to be due to hot weather, underwatering and stress. When I cut off the top, the cross section showed four holes, that looked like they were occupied by something white, that I think I lopped in half. Any ideas? The tree seems fine below the foot, but is dying slowly downward. Of course I'd love to save it.