Join the 2026 Contra Costa County SOD Blitz, taking place April 30–May 5, and help track the spread of Sudden Oak Death (SOD). You’ll be contributing valuable information towards understanding and slowing the spread of this oak-killing disease. There’s still time to register and participate.
Spend a few hours in your favorite park, open space, or neighborhood collecting samples of potentially infected leaves from California bay laurel trees, which can spread SOD to oaks. Have a picnic, make it a family outing, or just enjoy some quiet time alone with trees. No experience is needed, just a cell phone and a desire to help our iconic oak trees.
Here’s how to participate:
- Visit sodblitz.info to register and complete the 15-minute online training.
- Download the free SODMAP Mobile app (available for IPhone and Android) to see trees that were sampled in previous years and to get the coordinates of the trees you sample.
- Pick up your sample collection packet at the local SOD Blitz station:
Entrance to Fire Station #45 at 33 Orinda Way, Orinda, CA
Packets will be available beginning on April 30 at 10 am. - Collect bay leaf samples and record information in your packet.
- Return your packet to the SOD Blitz station where you picked it up:
Entrance to Fire Station #45 at 33 Orinda Way, Orinda, CA
Return packets within 24 hours of collecting samples and no later than 5 pm on May 5.
More information, including a 15-minute training video and online registration form, is available at sodblitz.info.
Background
Sudden Oak Death, a serious exotic disease, is threatening the survival of tanoaks and several oak species in coastal forests of California between Del Norte and Monterey counties. The disease spreads during wet years on leaves of California bay laurels and tanoaks. The presence of SOD-symptomatic bay leaves generally precedes oak infections.
Dr. Matteo Garbelotto, professor in the Department of Environmental Science, Policy, and Management at UC Berkeley, has been a leader in understanding SOD and the pathogen that causes it. He is hoping to mobilize a heavy turnout of volunteers to help track the disease in this year’s SOD Blitz.
Based on the bioblitz model used in field science, SOD Blitzes train citizen scientists to identify SOD on the leaves of California bay laurel, a plant the disease infects but doesn’t harm, and then search for and collect potentially infected bay laurel leaves for the Garbelotto lab to analyze. SOD Blitzes provide information to scientists and land managers about the spread of the disease and also allow broad genetic screening to detect a new and more aggressive form of the disease called NA2.
Volunteers are essential for tracking SOD, and you can make a difference by volunteering a few hours of your time for the 2026 Contra Costa County SOD Blitz. It’s a valuable contribution, no experience is needed, and it’s interesting and fun to do.
April 2026
