A University of California, Berkeley scientist says the rate at which trees in Marin County, California, became infected with sudden oak death in 2019 nearly doubled compared to the previous year, according to an article by KPIX 5 News.

The disease showed up in the mid-1990s and never went away. Sudden oak death is caused by a fungal pathogen, so it loves water. The heavy rains the region enjoyed coming out of the drought have caused infection rates increase dramatically in Marin County.

Tad Jacobs, a certified arborist and founder of tree care company Treemasters, says he’s been seeing quite a bit of the telltale symptoms throughout Marin County. He explains that these trees can go from green to brown in just a day or two, which is why it’s called sudden oak death syndrome.

Kerry Wininger of UC Cooperative Extension says you’ll see big patches appear at once and tree limbs that have fallen off. Wininger is with the UC team working to measure the problem, and she oversees a yearly survey conducted by volunteer citizen scientists.

She says that for Sonoma County, sudden oak death numbers look about double where they were last year, increasing at a rate a little bit faster than expected.

Researchers are fighting back with a campaign aimed at making the public more informed. According to Jacobs, people can try and mimic a native environment in their yard. They can avoid having a lot of water-thirsty plants that create a lot of moisture in the soil, as well as rhododendrons that are foliar hosts for sudden oak death syndrome.

The UC Berkeley Forest Pathology and Mycology Lab is hosting several North Bay meetings on Sudden Oak Death that will provide the public with information.