Boxwood Blight - Ask Extension
Can I bring in a sample and have you confirm if my boxwoods have the blight. its funny, my newer new ones look fine, but all of the3 originals have b...
Knowledgebase
Boxwood Blight #859731
Asked February 23, 2024, 3:10 PM EST
Can I bring in a sample and have you confirm if my boxwoods have the blight. its funny, my newer new ones look fine, but all of the3 originals have bit the bullet. And they are all right next to each other.
Montgomery County Maryland
Expert Response
If you are able to share photos of the symptoms here, that may be enough. We do not generally accept plant samples at HGIC, but if needed you might be able to go to your county Extension office (we recommend inquiring first).
Boxwood blight has fairly specific symptoms, including a fairly rapid and complete defoliation as the infection progresses, plus dark lesions on stems and foliage (at least, before they get completely brown or dried-out). Boxwood blight does not kill roots, so plants can regrow, though if infected repeatedly, the process of leaf loss and regrowth will eventually exhaust them and kill them. You can use the information on the linked page plus our boxwood diagnostic page to compare what you are seeing with typical ailments. We find that many mistaken diagnoses of boxwood blight are actually volutella blight or one or more overlapping conditions (like root stress and old winter damage).
Are all of the plants, new and older, the same cultivar? Susceptibility to infection can vary from one cultivar to another. Are any of the ailing plants closer to a roof downspout outlet, or covered with a thick layer of mulch? (While 2-3 inches of mulch is a typical recommendation, boxwood experts recommend using less since their roots are very sensitive to oxygen depravation from over-mulched or compacted soils. Heavy mulching can also encourage vole gnawing on the lower stems, killing branches or large sections of the shrub.)
Miri
Boxwood blight has fairly specific symptoms, including a fairly rapid and complete defoliation as the infection progresses, plus dark lesions on stems and foliage (at least, before they get completely brown or dried-out). Boxwood blight does not kill roots, so plants can regrow, though if infected repeatedly, the process of leaf loss and regrowth will eventually exhaust them and kill them. You can use the information on the linked page plus our boxwood diagnostic page to compare what you are seeing with typical ailments. We find that many mistaken diagnoses of boxwood blight are actually volutella blight or one or more overlapping conditions (like root stress and old winter damage).
Are all of the plants, new and older, the same cultivar? Susceptibility to infection can vary from one cultivar to another. Are any of the ailing plants closer to a roof downspout outlet, or covered with a thick layer of mulch? (While 2-3 inches of mulch is a typical recommendation, boxwood experts recommend using less since their roots are very sensitive to oxygen depravation from over-mulched or compacted soils. Heavy mulching can also encourage vole gnawing on the lower stems, killing branches or large sections of the shrub.)
Miri
