A recent phone call from a Gloucester resident sent Tree Stewards Bonnie Bernard, Chris Conley, and me on a quest to discover why a professional installation of 22 arborvitae resulted in several of the trees developing areas of brown discoloration. We did not find a definitive cause, but I hope we left the property owner armed with sufficient information to help pinpoint the cause. Upon arrival, we found a well-maintained, appropriately spaced, mixed border of “Emerald Green,” “Green Giant,” and “Junior Giant” arborvitae. Members of the cypress family, arborvitae are a popular choice to create lush, fast-growing borders. Originally thought to be less susceptible to fungal diseases than Leyland cypresses, arborvitae have proved to suffer from these problems, particularly if planted too closely together. “Emerald Green” is a 10 to 15 foot-tall, compact cultivar of the 50 to 60-foot-tall American arborvitae or white cedar (Thuja occidentalis), making it a more manageable option in home ga...