The San Francisco Chronicle recently published an update about Sudden Oak Death (SOD) that was both misleading and inaccurate.
The article inaccurately claimed that “the mysterious pathogen…has killed tens of thousands of oak trees from Big Sur to southern Oregon.” This is a gross underestimate of the number of trees that have been killed by SOD. The California Oak Mortality Task Force reported in the announcement of their 2009 annual symposium that “Since the 1990s more than a million oak and tanoak trees have died from this pathogen and at least another million are infected.” Since there is no known cure for the disease, we must assume those trees will die.
Secondly, the article quotes Matteo Garbelotto of UC Berkeley—who is described as “the nation’s foremost expert on sudden oak death”—as recommending that “homeowners in infected areas can remove bay trees…[to] increase the survival rate of nearby oaks.” We doubt that this is an accurate quote because it is not consistent with the advice Garbelotto gave at one of his SOD workshops.
One of the many professional gardeners attending that workshop asked if he should remove the bays in the gardens in which there are also oaks to protect the oaks from infection. Mr. Gabelotto’s response was that the bays would resprout ten-fold and that the immature leaves of the resprouts would be more susceptible to infection than the mature leaves. The gardener asked if he could prevent resprouts with Roundup. Mr. Garbelotto replied that Roundup would not prevent resprouts.
In other words, removing bay trees is easier said than done. Attempts to do so can result in even more bay trees unless toxic chemicals such as Garlon are used repeatedly to prevent resprouts. Since the immature leaves of the resprouts are more susceptible to SOD infection, this is not a wise strategy.
Garbelotto may have told the Chronicle that removing bay trees already infected with SOD may prevent the spread of the pathogen to oaks. Although it seems to us a risky strategy, it is apparently being done in the Santa Cruz Mountains, according to the San Jose Mercury (“’Sorry baby, but you gotta go’,” December 17, 2009). This is an important distinction: removing healthy bay trees is likely to do more harm than good, while removing infected bay trees may make some sense, although we would prefer to avoid the use of toxic chemicals.
Journalism is a powerful tool that can strengthen democracy if used responsibly, reporting the facts faithfully and balancing competing opinions when necessary. The author of this article grossly underestimates the number of native trees killed by SOD and offers bad advice about killing healthy trees. Those who still subscribe to the dwindling San Francisco Chronicle will not be surprised by such sloppy journalism. It is an example of the death throes of the Bay Area’s local newspaper.