Boxwood Blight

Protect Your Trees!


Boxwood Blight is a devasting fungal disease caused by the fungus Calonectria pseudonavicaulata. Box Blight results in rapid defoliation and decline in Boxwoods (including healthy plants). Box Blight is highly infectious and extremely mobile. It is easily spread throughout the landscape and nearly impossible to control.


A healthy plant is usually the first goal in our disease control recommendations. Unfortunately, this disease is not controllable with reasonable pesticide use. The current recommendations for control of Box Blight is 10 to 15 heavy fungicide sprays per season depending on the weather conditions. This constant fungicide presence will ultimately lead to chemical resistance in the blight and is still no guarantee of controlling the blight.


There are only a few specific cultivars showing any real resistance (not immunity) to Boxwood Blight. Once the blight becomes established on a property, even the resistant varieties an succumb to the disease.


With few exceptions, we are recommending to not treat for Boxwood Blight. Once the disease is found on your property an aggressive removal strategy should be started. Since the fungal spores are so easily spread, extreme care must be taken to limit the further spread of this disease.

Reinvesting in different species of plants is the best decision to be made. There are other species that resemble the Boxwood and are not susceptible to Boxwood Blight. Osmanthus, Mahonia and several cultivars of Holly are similar to Boxwood in shape and even texture, evergreen and deer-resistant. An even larger palette of plants is available in areas not browsed by deer.


Boxwood Blight will be devasting disease to our urban landscapes. While there is currently very little we can do to prevent or control this disease, there are plenty of beautiful plants that can be used as viable replacements.

If you think you have Box Blight on your property or would like to discuss options going forward, feel free to give us a call and set up a time to get together.