Mountain Ash tree seems to be dying - why?
I have a 30 yrs old Mountain Ash tree that has always been an attractive specimen in my back yard then all of a sudden in mid July - the leaves of 2/3's of the tree started to turn brown and the beautiful red berries looked dehydrated. The tree looks like if it's dying. 1/3 of the tree is green and healthy but the rest....awful!!! What can I do to save my tree?? I would be grateful for any advice that will help me.