In November of 2016, Boxwood Blight Disease was identified at a Burlingame residence. This is the first time this disease has been found in California, and it could have substantial impact on residential and community gardens. Boxwood Blight is a widespread fungal disease affecting boxwoods caused by Cylindrocladium buxicola (also called C. pseudonaviculata). Many varieties of both B. sempervirens and B. microphylla are susceptible to this disease, including many popular varieties of English and American boxwood.
The San Mateo County Agriculture Department and the California Department of Food and Agriculture (CDFA) are working with property owners to manage Boxwood Blight and to prevent its spread. The disease is easily spread from property to property on the tools and clothes of landscapers- education and good sanitation practices are vital in preventing the spread of the disease!
County Agriculture and CDFA are surveying other properties with boxwoods in the community to determine the extent of the disease and what regulatory response is needed. Please contact the San Mateo County Agricultural Commissioner’s office at (650) 363-4700 if you have boxwoods with suspicious symptoms. Instructions for best home garden management of Boxwood Blight disease are included below. There are also pictures of the effects of the Boxwood Blight available for download. Additional information about Boxwood Blight is available at the University of California Cooperative Extension website.