I have a beautiful 4-Clump River Birch that I had planted in my full sun back yard, 23 years ago, now full grown. Last year and this year, in the center of the tree, from bottom to the top the leaves came out "yellow" like when they turn in the Fall. The rest of the tree. on both sides of the yellow center section, are the normal Green color. Every Spring, for the last 5 years, I applied Bayer Tree & Shrub Protect & Feed and the tree did beautifully, until last and this year, when the Yellow leaves opened up. Our area is on Clay. WHAT IS THE PROBLEM. HELP!! PLEASE. Thank You!

Jean - I can only think of two reasons for yellow leaves, particularly on a birch. One is stress, the other is iron chlorosis. Iron chlorosis usually starts out with green in the vein area, and the rest of the leaf turns yellow. Those are both very possible scenarios in clay soil. It just seems weird to only happen to PART of the tree, unless there is a root problem. You might want to consider hiring a CERTIFIED arborist to check it out. Otherwise, check in with your local Master Gardener office: http://msue.anr.msu.edu/county/info/macomb and see if there is something "going around" in your area!