My Elm has a few yellowed leaves with dark areas located on most of the longer new-ish growth about halfway from the trunk to the tip. That is, say 40% of the distance out from the trunk is green and fine as is 40% in from the tip, but in the middel area, the leaves will fall when handled and are yellow. Of course, it has been very hot just this last week or 2 but most of the tree seems to be really in fine condition. The yellow leaves are a small fraction of the total greenery - just an odd thing. No insects that I can see so I suspect environmental.
any thoughts?
Carl