Question
I live in suburban Detroit and have a 7 yr old Jap Maple that mysteriously started to have several braches that did not get any leaves on this spring.  There are other branches that all leaves dried up several weeks after the leaves developed.  This affected about 1/3 of the tree, but the rest of the tree looks great.  I have since cut these brances off, hoping to spur new growth.  Did I help or hurt the situation, and what is the reason for the sudden death of these branches?

Answer
Eric,
There are two reasons why this could happen.
The first is the easiest to correct. The maple could have a girdling root. This is a root that instead of growing out away from the trunk, it was deflected backand has subsequently wrapped itself around the base of the tree. This condition will cut off nutrient flow and water flow from the roots to parts of the tree. To correct this problem, dig around the base to expose the offending root and cut it out in the fall.
The other reason I can think of is a vascular disease called verticillium wilt. This internal disase is not easily controled because it effects the vascular system. The way to identify this disease is to look at the dead and dying branches just under the bark. Healthy tissue will be green and white, a maple infected with verticillium will have black or dark brown streaks under the bark. The only control for this disease is direct fungicide injections into the tree and a regular fertilizer program to help the tree out grow the disease.
I would recommend checking the roots first.
Good luck.
Ed Gulliksen