Q.What would cause brown or dead looking branches on a emerald green arborvitae
Row of 16 year old emerald green arborvitaes 44 total. about 1/3 of them have a brown spot or dead spot on them. And all of them have yellowed tips.
Could this be wind damage or something more? Never had a problem since planted. They are about 18′ tall. Live in Massachusetts.
There are several possible causes for dieback on arborvitae branches. Winter kill, lawn chemicals, pruning so an area, often the bottom, doesn't receive enough sunlight and water stress. There may be a bit of life in the browned areas. Keep them watered this growing season before pruning out the dead-appearing branches next year. There is a canker that affects Aborvitae, Seiridium canker. It is most common in Leyland cypress but arborvitae can be affected, too. The following link takes you to an article on this disease. https://hnr.k-state.edu/extension/info-center/common-pest-problems/common-pest-problem-new/Arborvitae%20Seiridium%20Canker.pdf