I planed a row of 60+ arborvitaes about 6 years ago. for the most part they are all growing and healthy. Every summer, I get a random 1 or 2 7' healthy trees that start by turning yellow on only 1/2 of the tree then that yellow turns to brown and eventually, the entire tree dies. There are no signs of disease or bugs or vines on the trees. How can I stop the slow death of my trees. They are getting plenty of water, not too much and not in a wet area.
Montgomery County Pennsylvania
What does the root system look like when you take out the dead trees? Most of the research I have done suggests that browning like you describe is usually an issue with either too much water, like it is maybe ok on the surface, but when you dig down a little bit, it's really soggy, or that the browning is from drought conditions. It could also maybe be from the way it was planted. Could the root system be stuck in the covering around the root ball? Some retailers use the burlap-like covering, and it really doesn't disintegrate.