Sudden Oak Death in Sonoma County

Where is Sudden Oak Death in Sonoma County?

A wet winter and spring is good for plants and it’s good for pathogens, too. The sudden oak death (SOD) pathogen requires water and temperatures around 70 degrees F to spread naturally. Some years are “good” for the pathogen, and some are dry and not good for the pathogen. The weekend of April 17th we are going to find out if conditions are “good” for (SOD) to once again spread through our county. And you can participate… read on.

The Sonoma County UC Master Gardener SOD Specialists will be hosting a Sudden Oak Death Blitz, April 17, and are asking all Sonoma County residents concerned and curious about SOD to participate in this weekend citizen science project. All ages welcome. After this weekend you will have a good idea of where SOD is throughout Sonoma County, and what symptoms to look for

1. Attend a Saturday morning meeting on April 17th .

Here you will learn how to identify and collect symptomatic leaves from SOD host trees.

There will be two meetings in Sonoma County:

· 9-10:30 am at the Environmental Discovery Center in Spring Lake Park, 5585 Newanga Avenue, Santa Rosa

· 10-11:30 am at the Healdsburg Branch, Sonoma County Library, Piper St at Center St, Healdsburg, CA

At this meeting you will learn where SOD is in Sonoma County and how to recognize symptoms of SOD infestation.

2. Go look at your trees and collect samples.

Spend some time Saturday or Sunday inspecting the trees in your yard or somewhere else within the County (with permission, of course). We can suggest places for you to collect leaves if you don’t have a place in mind.

3. Return samples Sunday afternoon, April 18th.

There will be a drop-off site for your leaf samples. From here they will be driven to a UC Berkeley pathology laboratory for diagnostic testing.

4. Get a notification of the results as soon as they are available.

5. Attend a meeting where UC Berkeley Plant Pathologist, Dr. Matteo Garbelotto, will discuss the results and what they mean for Sonoma County.

To participate, just come to a meeting. If you can, RSVP to this email or the Master Gardener help desk, 565-2608. For more information go to or call the help desk.

Lisa Bell
Agricultural Program Assistant
Sonoma County UC Cooperative Extension
133 Aviation Blvd., Suite 109
Santa Rosa, CA 95403
(707) 565-2050

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