Question
Jim. this may be out of your expertise but let me give it a try. I am about 5 miles from the Maryland coast in a wooded community. I have planted my second American dogwood in sandy to clay soil. The first died from what I believe was from geting wet feet. This one I planted high and it seems to be doing well. My question concerns the mulch under the tree. I have used shredded hardwood bark which lasts but ends up pretty well packed after a season. Should I rake this loose in the spring to allow more air to get to the roots or will the raking damage the root system? I have also recently read that hardwood mulch actually promotes some diseases and I wonder if it should be removed and replaced with something like pine bark?  

Answer
The mulch is to keep weeds from growing around the tree, hold moisture and keep lawn mowers away from the trunk. As long as you do not use dogwood bark or leaves there should be not problem. Only put about three inches deep of mulch at a time. There is no need to rake the old off. The mulch will decay over time and become good duff and soil material. Hardwood bark is not a problem --I prefer pine straw but it is a personal choice.