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.



Nursery inspections continue in California, Oregon, and Washington. Read more…

Waterways in Washington found positive for P. ramorum. Read more…

New updates in fire research, modelling, citizen science, and more just released. Read more…

Become a Sudden Oak Death Citizen Scientist. Join the Cause – Make a Difference!

Resources on P. tentaculata, recently found in native plant nurseries and restoration sites.

New THANQs – FAQ Resource for Tree Health Questions

Read the latest newsletter.

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

5/15 – San Luis Obispo SOD Blitz Training; San Luis Obispo UC Cooperative Extension

5/16 – Woodside, Portola Valley, Atherton, Emerald Hills, and Belmont SOD Blitz Training; Woodside Town Hall

5/23 Carmel Valley  SOD Blitz Training; Carmel Valley Garland Ranch Regional Park Museum  Hall

5/30 – Marin SOD Blitz Training; Dominican University of California

4/28 – Sonoma SOD Blitz Training; 3 locations from which to choose

See the entire events calendar.