Boxwood Blight

Boxwoods are a very common landscape plant. You often see them around the front of houses or porches. Unfortunately for boxwood lovers, they are pretty susceptible to some major problems.

Boxwood blight, or box blight, is a fungal disease new to the Eastern U.S. The pathogen infects leaves and branches of the boxwoods, causing light or dark brown leaf spots with a darker border, defoliation, and dieback. In warm conditions the fungus will produce white spores on the undersides of leaves and stems. Repeated defoliation and dieback can cause plants to be more susceptible to other diseases, such as Volutella blight (Dart, Hansen, Bush, & Hong, 2011).

Browning and defoliation 

Leaf spot

Black stem streaking

All known species of boxwoods are susceptible to box blight. The pathogen can spread by wind, rain, or splashing water. Spores can also be spread by birds and insects. The scary part about box blight is that the pathogen has been found to survive for up to five years (Dart et al., 2011).

Today Suzanne, Holden, and I went to Lamsburg with Brian Kreowski from VDACS to assess boxwood blight affecting some nurseries. I was instructed to wear bad clothes and shoes that I wouldn't be wearing spreading the pathogen around. This is because the pathogen can survive for a long time even on clothing and shoes. Brian told us that many of the boxwoods that were in these nurseries the year before had already been removed. The affected nurseries were under order by VDACS to stop selling boxwoods and also to remove affected plants and destroy them. We went to see if there was any more spread of the disease and assess the situation.

We only saw symptoms of blight on just a few boxwoods in one area of the nursery, which is good! Box blight can be absolutely detrimental to a nursery, sometimes even killing plants that have been around for over 50 years.

Before we left at the end of the day, we sprayed off our boots and the bottoms of our pants to try to kill any pathogens that may have gotten on them. I was also given a card from the Virginia Cooperative Extension that is used to help recognize the symptoms of boxwood blight: leaf spot, browning and defoliation, and black stem streaking. I also learned that Extension also has a Virginia Boxwood Blight Task Force. This service provides information on avoiding, managing, and sampling for boxwood blight.

Dart, N., Hansen, M., Bush, E., & Hong, C. (2011). Boxwood Blight: A New Disease of Boxwood
          Found in the Eastern U.S. InVirginia Cooperative Extension. Retrieved October 20, 2015, from           https://pubs.ext.vt.edu/PPWS/PPWS-4/Boxwood_Blight_pdf.pdf