ANNAPOLIS, MD. The Maryland Department of Agriculture urges Maryland residents buying fresh, holiday decorations to use caution with holiday greens that contain boxwood. By using boxwood greens you could potentially introduce a serious fungal disease called boxwood blight to surrounding boxwoods.
During the holiday season, people often buy natural decorations, such as garland or wreaths to adorn their homes or businesses. Boxwood is a common evergreen shrub that is found in the yards of many Maryland homeowners and is often used as a base for wreaths in holiday décor. Boxwood blight, also known as box blight, is a new, aggressive disease that causes defoliation and decline of susceptible boxwoods.
Boxwood blight is caused by a fungus called Cylindrocladium pseudonaviculatum. Initially, the disease may show few or no symptoms in the nursery, especially if plants are sprayed with fungicides. However, when infected plants are exposed to favorable conditions of moisture and temperature, severe blight and decline can occur. Visible signs of boxwood blight include brown spots on leaves that then lead to defoliation and black lesions (cankers) on the green stems of the boxwood. This fungus also produces sticky spores, which can be easily transported by human activities. The major means of transmission for boxwood blight is through the movement of infected plants and contact with contaminated clothing, tools, or equipment.
Boxwood blight was first found in the United States in 2011 and has since been reported in over 20 states as well as Canada. This disease was first seen in Maryland in 2013 and reported cases have been increasing each year. This fall, boxwood blight was found in boxwood wreaths that were for sale in a Maryland store.
The Maryland Department of Agriculture monitors our state’s nurseries. If boxwood blight is found, all infected plants are destroyed and sites are cleaned to avoid further spread of the disease. If your holiday decorations display signs of boxwood blight, double bag the suspected décor and place it in the trash. Avoid composting the suspected plant. If boxwood greens must be used for decorating, be sure to place further away from other boxwood plants in your landscape.
For more information about boxwood blight and symptoms, visit the department’s fact sheet here. Contact the Maryland Department of Agriculture’s Plant Protection & Weed Management program at 410-841-5920 for any concerns related to boxwood blight.