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.”

Registration for The Sixth Sudden Oak Death Science Symposium now open!

Recent monitoring at the previously-positive Kitsap County botanical garden has not recovered Phytophthora ramorum. Read more…

Three samples from eastern forests were positive in the 2015 national survey. Read more…

Midpeninsula Regional Open Space approves $500K for research and management. 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

5/14 – Sonoma SOD Blitz Trainings; 4 locations

5/14 – Portola Valley SOD Blitz Training; Portola Valley Town Center

5/14 – Los Altos Hills SOD Blitz Training; Los Altos Hills Town Hall

6/21 – 6/23/16 – Sudden Oak Death Science Symposium 6;
San Francisco

See the entire events calendar.