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.



Two new P. ramorum-positive plants confirmed at the Kitsap County, WA botanical garden. Read more…

In 2015, CDFA tested more than 7,000 plant, water, and soil samples for P. ramorumRead more…

Across the country in 2015, P. ramorum was recovered from 18 nurseries, one commercial landscape, two residences, and a botanic garden in non-quarantine areas. Read more…

The Sixth Sudden Oak Death Science Symposium: Biosecurity, Plant Trade, and Native Habitats will take place June 21-23, 2016 in San Francisco. We invite you to submit papers and posters by January 29, 2016. See the conference website, call for papers and sample abstract for more details.

Read the latest newsletter.

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

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

2/23 – 2/24/16 – Observatree/ IPSN Conference on Tree and Plant Health Early Warning Systems in Europe; Royal Botanic Gardens, Kew, UK

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

See the entire events calendar.