The cedar hedge in my yard is dying and I'm not sure why. I have attached a picture which shows the hedge. The brown trees died last fall and the lighter brown ones have just recently died. I have had the soil tested and it shows to be in good condition. I have checked for spider mites but there don't appear to be any. I have checked the base of the trees and there don't appear to be any holes or any obvious issues. These trees have been fine for at least 6 years prior to dying and my neighbours trees are all fine. I want to replace the dead trees but would like to know why these ones died so that the new ones don't just die as well. Any advice is very much appreciated. Thanks!!!