Reporter's Notes: Sudden Oak Death

There is no proven cure for Sudden Oak Death. But that doesn't mean you can't find people selling cures.

In fact, the Internet is full of theories – and their related products – that explain how to treat Sudden Oak Death. The problem with them, says UC Berkeley researcher Matteo Garbelotto, is that they don't work. And in fact, he adds, they could actually harm people's backyard oak trees.

One of the most popular treatments says that part of the problem with oaks is that they're weakened by acidic soils (presumably from acid rain), and the theory is that heavy doses of calcium in the soil could restore natural balance and strengthen trees against the Sudden Oak Death pathogen. In hopes that the theory might bear fruit, the Garbelotto lab recently tested it.

The study found that it did nothing to stop the Sudden Oak Death pathogen. In fact, Garbelotto said, it's like giving a glass of orange juice to someone with a terminal disease. And in some cases, he added, it could have a detrimental effect.


A different Garbelotto study showed that a phosphonate fungicide, brand-named Agri-Fos, can prevent the onset of Sudden Oak Death, for a period of about two years. This is the only product on the market that is effective, he said – not as a cure, but as a two-year preventative.

Some people who love their oak trees decide to try both treatments, Garbelotto said. And since the phosphonate that does work is acidic, and the calcium treatment that doesn't work is basic, then you could end up inhibiting the treatment that actually works. That is, if you use both treatments, he said, the calcium could actually negate the positive effect of the phosphonate.

From 10 a.m. to noon on Sunday, May 16, Garbelotto will lead a "Sudden Oak Death Blitz" at the East Bay Parks Botanic Garden in Berkeley's Tilden Park. The event, sponsored by the California Oak Mortality Task Force, trains participants to spot vegetation infected with P. ramorum and collect samples for testing. The training is useful for homeowners who want to monitor their own trees for Sudden Oak Death.

Listen to the Sudden Oak Death radio report online.

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