Hi, My boxwood is along a garage and faces south but has some shade because of a beautiful oak that is situated in our garden. At the beginning of the season there were some brown areas on the bush but they seem to be out of control especially along the back (garage side). I believe my husband used a copper spray in April/May but I would like an opinion of what you think we should do at this time. Many thanks
Thank you for contacting the Toronto Master Gardeners.
Unfortunately, your boxwoods have been affected by a relatively new invasive moth–the Box Tree Moth (Cydalima perspectalis).
Here are some links about the moth and how to control it. However, the main recommendation is for the use of BTK–a biological insecticide available at stores such as Home Hardware, Canadian Tire, etc. It’s important to use this product when recommended.
We hope that you have success in dealing with this moth and that your boxwood will recover.
July 26, 2021