Is this Boxwood Blight?
We have a number of well-established boxwoods in our front and back yards. A couple in the backyard have experienced serious leaf-loss in the past month and we're concerned about boxwood blight. Does that seem like a possibility? See first two photos. The third photo from front yard shows boxwood that doesn't look too healthy, but no leaf loss has occurred. Could this be something different? If this is blight, is the only recourse to totally remove the affected bushes? We hope not to lose them all!
Montgomery County Maryland
Rapid defoliation is a symptom of boxwood blight. Another symptom is small black lesions on the stems, which look like dashes made with a black marker. It looks like those lesions are present in your first photo. Please see our article with close-up photos of the symptoms of boxwood blight and what to check for. https://marylandgrows.umd.edu/2019/04/01/boxwood-blight-in-maryland/
Boxwood blight is not a curable plant pathogen. You will have to remove infected plants and leaf debris and discard everything in the trash. We do not recommend re-planting boxwoods in the same location. All plants in the Buxaceae family including sweetbox (Sarcococca sp.) and spurge (Pachysandra sp.) are susceptible to boxwood blight.
Diseased plants and any fallen leaves should be removed, bagged, and disposed in municipal waste or buried 2' deep in soil away from boxwood plantings. Remove leaf litter from the soil surface by vacuuming, raking, or sweeping.
This fact sheet from Virginia Cooperative Extension provides the best current information on how to management boxwood blight in a landscape setting. Take note of the section on sanitation. Any tools and equipment used on symptomatic boxwoods will need to be sanitized in order to prevent spreading the pathogen to healthy boxwood plants.