Nursery and Christmas Tree

Cylindrocladium buxicola (syn. C. pseudonaviculatum), a fungal disease of boxwood commonly known as boxwood blight, is not native to the US. The pathogen was most likely transported to the US on boxwood from nurseries in Europe.

  • First known find in Pacific NW: At a nursery in Washington County, Oregon in December 2011
  • Found in the eastern US: At nurseries in Surry County, North Carolina and Carroll County, Virginia, and at a residential landscape in Middlesex County, Connecticut in October 2011

All boxwood species may be susceptible to blight, however American boxwood varieties appear to be particularly vulnerable. The boxwood family Buxaceae and a member of this family, Sarcococca, have been shown to be susceptible to the fungus C. buxicola.

Symptoms

  • Light or dark brown circular leaf spotting
  • Black longitudinal or diamond shaped lesions on stems
  • Results in defoliation of leaves and an overall straw colored appearance of the plant

Disease transmission is increased in moist environments, making host plants in greenhouses particularly susceptible. The fungus can form resting structures (chlamydospores and microsclerotia) that can survive for years on host organic debris in the soil. Mortality most often occurs in seedlings, but may also take place in older plants, especially if infected with a secondary pathogen. 

Nursery Cleanliness Program for Boxwood Blight

This voluntary program of inspections and best management procedures is designed to help a nursery provide clean boxwood nursery stock to their customers with more confidence. Please see the Nursery Cleanliness Program document for more information on how to enroll.​

Resources

Boxwood blight fact sheet

Symptoms, transmission, and geographic distribution Document

Boxwood Blight Nursery Cleanliness Program

Document

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​Contact

Main Office
Nursery & Christmas Tree
635 Capitol St NE
Salem, OR 97301
Phone: 503-986-4644
Fax: 503-986-4786
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