Wow, good info! We had our house built 2 years ago. They planted a pin oak and put a big mulch ring around it. Wish I had known sooner, I would have pulled all the mulch away. Will be doing that tomorrow for certain now. Also, I will be looking into doing the fertilizer rings as recommended in the article on chlorosis. I will be calling the extension office to see about soil testing. I don't want to lose the pin oak, I love those trees!