The results of the 2023 Sudden Oak Death (SOD) Blitzes were released on Nov. 17 by Matteo Garbelotto of the UC Berkeley Forest Pathology and Mycology Laboratory. Each year citizen scientist volunteers collect symptomatic foliage in their local communities in order to track the rate of SOD. The samples are then tested at University of California, Berkeley. This year there were 28 district locations across central and northern California. Over 10,000 trees were surveyed over 145,000 acres and 1,900 samples were turned in for analysis by the more than 400 volunteers who were trained online and assisted in the blitz.
Owing to last year's wet winter, it was expected that there would be an increase in the SOD pathogen, but, fortunately, infection rates only increased in a few regions, including Sonoma, Carmel/Big Sur and the West Peninsula. Rates in the East Bay and elsewhere were relatively constant.
The areas east of the Berkeley-Oakland hills were mostly devoid of active outbreaks. However, outbreaks in the northern and western parts of the East Bay were numerous and included UC Berkeley property, North Berkeley and El Cerrito. Plant nurseries, including the UC Berkeley Botanical Garden and Tilden Park were negative.
However, it is possible that SOD will steeply increase in the next year, and UC Berkeley Forest Pathology and Mycology Laboratory recommends that for residents with coast live oaks, Shreve oaks or black oaks on their property, this may be the time to actively protect trees. First and foremost, oak owners are advised to eliminate small and medium sized bay trees up to 20 inches in diameter with canopies within 15 to 30 meters from the trunk of an oak tree. For high value trees, treatments with phosphite in conjunction with gypsum amendments may also be recommended, and pruning of large branches or of stems at the end of November should be avoided.
Further information about the annual survey and results, including videos on how to protect trees, may be found at sodblitz.org
Owing to last year's wet winter, it was expected that there would be an increase in the SOD pathogen, but, fortunately, infection rates only increased in a few regions, including Sonoma, Carmel/Big Sur and the West Peninsula. Rates in the East Bay and elsewhere were relatively constant.
The areas east of the Berkeley-Oakland hills were mostly devoid of active outbreaks. However, outbreaks in the northern and western parts of the East Bay were numerous and included UC Berkeley property, North Berkeley and El Cerrito. Plant nurseries, including the UC Berkeley Botanical Garden and Tilden Park were negative.
However, it is possible that SOD will steeply increase in the next year, and UC Berkeley Forest Pathology and Mycology Laboratory recommends that for residents with coast live oaks, Shreve oaks or black oaks on their property, this may be the time to actively protect trees. First and foremost, oak owners are advised to eliminate small and medium sized bay trees up to 20 inches in diameter with canopies within 15 to 30 meters from the trunk of an oak tree. For high value trees, treatments with phosphite in conjunction with gypsum amendments may also be recommended, and pruning of large branches or of stems at the end of November should be avoided.
Further information about the annual survey and results, including videos on how to protect trees, may be found at sodblitz.org
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Lamorinda Weekly, Moraga CA