Sudden Oak Death (SOD) is the term used to describe a disease that was recently identified in the Corte Madera and Los Trancos Creek watersheds which includes our neighborhood.  The "water mold", Phytothera ramorum, that causes the disease spreads during wet weather using host plants such as Bay Laurel.  Although P. ramorum does not kill the host plants, it will cause leaf spots or browning.  P. ramorum can kill 4 varieties of local Oaks and Tanoak.  Red sap leaking from lesions in the lower trunk often precedes the sudden death of affected trees.  

SOD has become a progressive problem in coastal Washington, Oregon and Northern California since the mid-1990s leading to the loss of over a million oaks in infected regions.  Now SOD has worked its way into our area with potentially devastating effects.  The presence of SOD, be it in infected host plants or diseased Oaks, has been positively identified in both Los Trancos Woods  and Vista Verde.