Given numerous call regarding diseased oak trees in Palo Alto, the City’s Planning Arborist, Dave Dockter, has provided information regarding "sudden oak death" (SOD), which is an oak tree epidemic killing populations of coast live oak, black oak and tanoak trees at an unprecedented rate throughout California. Trees that are already stressed by environmental and biotic factors, are usually the ones that fall victim to the fungus and the beetles that feed off of it, and the trees can die from within months to two years.
After being weakened by a fungus, the tree then succumbs quickly to opportunistic beetles. The beetles strike quickly resulting in rapid and irreversible decline and death. Dave says that "beetle impact can appear quickly. Without warning symptoms, it's as if a shotgun blast shot hundreds of tiny holes in the trunk and scaffold branches, with red and white ooze exuding". There have been SOD deaths reported in the Palo Alto Foothills Park, and the park is being monitored by Parks staff. As in most Bay Area Counties, Santa Clara County is under a State quarantine restriction, prohibiting movement of any oak firewood over county lines.
WHAT YOU CAN DO
According to the University of California Cooperative Extension in Marin and California Oak Foundation, proper care can help prevent Sudden Oak Death and ambrosia bark beetle attacks around specimen oaks in the Palo Alto landscape. The City of Palo Alto has prepared a Best Management Practices for Sudden Oak Death handout. These practices are consistent with the existing State of California and County of Santa Clara/San Mateo regulations currently in effect. The handout is also available at the Development Center.
