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.



EU1 lineage confirmed in U.S. forests for the first time, suggesting pathogen spread from nurseries to wildlands. Read more…

Five new waterways confirmed in northern California. Read more…

Additional P. ramorum finds at Kitsap County, WA botanical garden. Read more…

Redwood National Park continues “slow the spread” treatments. Read more…

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

8/23 – 8/28 – 5th International Workshop on the Genetics of Tree-Parasite Interactions; Orléans, France

9/21 – 9/25 – 63rd Western International Forest Disease Work Conference; Newport, Oregon

10/21 – SOD Treatment Workshop; UC Berkeley 

11/4 – 11/5 – Annual Meeting of the California Forest Pest Council; Wildland Fire Training & Conference Center, McClellan CA

See the entire events calendar.