McGowan English Boxwoods
Hi, I have a large 60 year old boxwood that looks very sad. Don’t know if it’s the dreaded boxwood blight or something else but it is spreading from one boxwood to the next. Is there a spray I can use to stop the dropping of leaves. Anne
Montgomery County Maryland
Unfortunately, the black lesions we see on the leaves of your plant are a symptom of boxwood blight. Black streaks on the stems are also a diagnostic characteristic of this disease. There are good photos of the symptoms for comparison in this article by our plant pathologist. https://marylandgrows.umd.edu/2019/04/01/boxwood-blight-in-maryland/
The fungal pathogen that causes boxwood blight can spread very easily to healthy boxwoods by way of contaminated tools, equipment, clothing, etc. Careful sanitation is essential for minimizing the spread of the disease. Infested plant material should be removed from the site (not composted). Fungicides can prevent symptoms on healthy boxwoods, but they will not cure existing symptoms. Refer to the recommended practices for managing boxwood blight in this fact sheet from Virginia Cooperative Extension.