What is Sudden Oak Death?

Sudden Oak Death is a tree disease caused by the plant pathogen Phytophthora ramorum. The disease kills some oak species and has had devastating effects on forests in California and Oregon. Read more about Sudden Oak Death.

Areas of Interest

P. ramorum in Wildlands The information in this section is geared toward land management, forestry and arboriculture professionals, including Best Management Practices.
P. ramorum in Nurseries This section addresses P. ramorum issues critical to nurseries, independent growers, and related plant-care/plant propagation industries, including Nursery Diagnostic Guides.
P. ramorum
in the Urban Interface
Look here for resources that address common homeowner questions, including diagnosing Sudden Oak Death and finding an arborist to work with.


The California Oak Mortality Task Force is a task force under the California Forest Pest Council.



Have you read the recent media reports about the failure to eradicate P. ramorum in California? Read the full back story in our latest briefing paper.”

Forest monitoring efforts confirm P. ramorum in Alabama, Mississippi, and Oregon. Read more…

Retail and interstate-shipping nurseries in California confirmed positive for P. ramorumRead more…

USDA APHIS revised regulations on the interstate movement of regulated soil from P. ramorum quarantined areas. Read more…

Patent approved for use of Trichoderma to remediate P. ramorum-infested soil. Read more…

Read the latest newsletter.

Resources on P. tentaculata, recently found in native plant nurseries and restoration sites, can be found on the new CalPhytos.org web page.

New THANQs – FAQ Resource for Tree Health Questions

Help stop the spread of forest pests – including Sudden Oak Death – on firewood! Check out the website of the California Firewood Task Force.

Calendar of Events

7/29 – 6th Sudden Oak Death Science Symposium Proceedings submission deadline; Author instructions are available at http://ucanr.edu/sites/sod6/Proceedings/.

See the entire events calendar.