Incidences of Sudden Oak Death in California are being monitored to combat the disease. Residents in Los Altos and Los Altos Hills recently gathered to learn how to treat and protect trees from the disease, where so far few trees have been infected. Researchers at UC Berkeley have predicted that the disease could eliminate 90% of California’s black oak and live oak trees with 25 years if steps aren’t taken to control it. A survey of the area’s trees conducted in May showed that nearly 10 times more trees were infected with the disease than the previous year, with the highest incidence in East Bay, Saratoga, and Sonoma. Los Altos and Los Altos Hills are thought to have a low disease incidence because of the landscaped nature of the area with less native vegetation.
Sudden Oak Death showed up in California less than 25 years ago when infected California bay laurels and other infected plants were introduced into the landscape. Laurels can have the disease without dying, but once an oak gets the disease, it will die. Oak trees can be treated with an annual injection or bark application of phosphite, which has minimal environmental impact and increases resistance to the disease.
Residents can help stop the spread of the disease by cleaning garden tools and vehicles of soil and debris from infection sites and buying ornamental plants from nurseries that test for the disease.