I have an Autumn Purple Ash tree that dropped its leaves unusually early last year. Your expert gardeners advised me that it was a fungus that would die off in the winter and wouldn't hurt the tree unless it happened several years in a row. This tree is always the last in the neighborhood to sprout leaves in the spring and I'm usually away from home when it happens so I don't know its usual habit. This year it has (so far) produced about 1/3 of it's usual leaves and they're growing in about 20 patches at various places on the tree while the other branches are still bare. Also, in the past this tree has put out about 3-4 inches of new stem from the ends of branches before leaves appear. This didn't happen this year. Should I be worried?
This past winter was so devastating that it is probable that not only was the fungus killed, but some of the branches of the tree might have been damaged as well. It is possible that the tree needs to be pruned, and the bare branches removed in order to stimulate growth. Shaping the tree while pruning might be in order too. Check with a registered arborist in your area to see exactly what state of health the tree is in, whether the fungus has returned or whether this is evidence of the winter's ravage , and you will get the advice you need.