Leslie Hollandsworth is a Plant Inspector II for the Tennessee Department of Agriculture. Leslie keeps me updated on the latest pests and diseases that have been identified in Shelby County. Leslie confirmed that boxwood blight has been discovered in a residential landscape in Memphis.
Boxwood blight is a disease caused by the fungus Calonectria pseudonaviculata. It was first discovered in North Carolina and Connecticut back in 2011. Boxwood blight can be found on landscape plants, containers and Christmas decorations such as wreaths and garland that are made with boxwood foliage.
Symptoms of boxwood blight are leaf spots, twig lesions and leaf drop. Severe leaf drop can occur when conditions are favorable for infection. This can happen anytime during the growing season when the temperature ranges between 65 and 75 degrees Fahrenheit and foliage stays wet from either irrigation or rainfall. Infected plants may start to defoliate when the conditions are favorable for infection.
Boxwood blight can be introduced into landscapes on infested nursery stock. Quarantine new boxwoods for two to four weeks before introducing them into your landscape. Practice good sanitation by disinfecting tools and equipment between plantings and pruning.
Be sure to wear disposable gloves when collecting specimens for disposal where boxwood blight may exist. If you suspect boxwood blight in your landscape, bag the infected plants and dispose of them in a landfill. It may also be a good idea to use a shop vacuum to remove fallen leaves from infected plants. Lastly, protect other boxwoods in the area with a fungicide spray specifically used to treat leaf spots.
Recognizing the symptoms of boxwood blight and following good sanitation is critical for management of the disease. Please contact me at the Shelby County Extension Office (901-752-1207) for more information on boxwood blight diagnosis. Let’s do our part to reduce the spread of this serious disease!
Happy Holidays to you and your family!