What is causing one of my arborvitae trees to turn yellow?
I planted eight arborvitae trees three years ago in a river bed. The soil there is very rocky. Seven are doing very well, very green. This season in late spring the one in the direct middle of them started to turn yellow. It's not dead, but it has more yellow than green. I have a service that deep root fertilizes them every fall. I can't figure out what's going on with this one tree. There is no black on the bark. What can I do to save this tree?
Luzerne County Pennsylvania
Your tree may have a problem with root rot. I suggest taking a sample of the root and foliage to your local county extension office. They will send the samples to Penn State for analysis.