Federal quarantine regulations for Phytophthora ramorum are developed by the United States Department of Agriculture – Animal and Plant Health Inspection Service (USDA-APHIS). The entire states of California, Oregon, and Washington are regulated to limit the spread of P. ramorum from nurseries. Additional quarantine regulations are in place in the 14 California counties and partial area of Oregon with wildland infestations. See the map at right or download a printable copy. Find more information at the USDA-APHIS P. ramorum page.
California and other states
The California state Phytophthora ramorum quarantine harmonizes with the federal regulation. The California Department of Food and Agriculture (CDFA) implements quarantine policy for California with enforcement conducted by county agriculture departments. See more detail on California’s statewide quarantine on the CDFA website. Businesses or individuals with questions concerning movement of host nursery stock, firewood or other materials made from host trees or plants can contact their county agricultural commissioner’s office – see the California County Contacts page for more information.
The National Plant Board is a non-profit organization of the plant pest regulatory agencies of each of the states and Commonwealth of Puerto Rico. Regulations for the shipment of nursery and greenhouse stock for each of the 50 states are available at http://nationalplantboard.org/laws/index.html
To prevent further introductions of P. ramorum, the United States regulates importation of nursery stock into the USA. See the April 18, 2012 order from APHIS for more information.
International standards require pest risk assessments to evaluate the need for quarantines. Phytophthora ramorum risk assessments from several countries are available on our Pest Risk Assessments page.
* This page was updated in 2012. Regulatory information previous to that time is stored in our Historical Archive.