Answer: Unfortunately, based on your description I am not able to tell you what is wrong with your arborvitaes. Spraying without having a specific diagnosis is very often ineffective -- many problems must be treated with a particular product at a specific time of year or stage of development for the treatment to do any good. I would strongly suggest you consult with your local county extension for help in identifying the problem. Then, knowing that, they can help you determine how to help them along. If it is something that needs a chemical control they will be able to tell you specifically what to use and how/when to apply it. They should also be able to help you analyze the growing location to try to troubleshoot any possible contributing environmental cause, or see if there is anything you can do to "baby" them a little while they recover. Best of luck with your arborvitaes!
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