Sudden Oak Death Disease Inspection


Phytophora ramorum is fungus disease in oak trees that causes sudden death to members of this species, by interfering with the trees’ ability to transport food and water. The disease may be spread by the movement of nursery stock and other products made from unprocessed wood or wood products. There are many hardwood trees and shrubs that can spread the fungus. The disease occurs in the following counties in California, Alameda, Contra Costa, Humboldt, Lake, Marin, Mendocino, Monterey, Napa, San Francisco, San Mateo, Santa Clara, Santa Cruz, Solano, and Sonoma. The Federal Quarantine prohibits the movement of host material from the quarantine area into areas where the fungus is not established in order to protect and preserve the oak trees and oak woodlands, that are such an important part of the landscape in many areas of California.

Commercial nurseries who wish to ship products from the quarantine area must have a certificate issued by an authorized agricultural official affirming that the articles and commodities have been:

  • Produced and maintained in an area which has been inspected to assure that the articles are not infested
  • Grown in a manner that prevents infestation
  • Tested and found to be free of the pest.


Ventura County is a non-infested county and The California Department of Food and Agriculture contracts with the Agricultural Commissioner to conduct inspections in nurseries that ship host material interstate and to sample and test for the presence of the disease. This helps to prevent the spread of the disease from the infested area. This program is a part of the Pest Exclusion and Plant Protection Division.


NOTE: As a convenience to our visitors, this page may contain links to external websites that are not managed or controlled by the County of Ventura.