A: Yes, tests have confirmed the presence of Sudden Oak Death for the first time in San Luis Obispo County.
This is a serious exotic disease that is threatening the survival of tanoak and several oak species in California, including coast live oak. Sudden Oak Death is now found in 16 coastal counties, from San Luis Obispo to Humboldt County. The disease spreads from infected California bay laurel leaves to oaks.
Management options are available, but they are only effective if implemented before oaks and tanoaks are infected, so timely detection of the disease on bay laurel is essential.
Hosts, such as California bay laurel, suffer less damage and do not die from the pathogen. Despite this, the bay laurel is significant because it can harbor and spread the disease.
Diagnosing the disease is tricky. A laboratory test using either culture techniques or DNA analysis is necessary to confirm the presence of Phytophthora ramorum. Once the pathogen’s presence is confirmed, proper disposal of leaves, twigs and branches is an important step toward limiting the spread of the disease. Removal of the tree or infected plants may be necessary.