Browning leaves on winter gem boxwood
Hi - It looks like there are minor symptoms of boxwood leafminer injury and some cold damage from the late frosts in May. We have been seeing reports of both from various locations. Here is our webpage about boxwood leafminer and what to look for, https://extension.umd.edu/hgic/boxwood-leafminer-shrubs.
Our recommendation is to prune and thin your boxwoods, which will help to reduce the population of the leafminers. (By now they will have laid eggs in the leaves.) They have only one generation per year. Prune out and dispose of the clippings in your trash. Please watch our video which has a demonstration of how to correctly prune and thin boxwoods, https://youtu.be/3i8mcoKapeY Thinning also will help with management of common fungal diseases of boxwoods.
Visit our website for further information about preventing common pests and diseases of boxwoods.