San Francisco has been making a concerted effort to lower the use of pesticides and herbicides on city-owned property. By overall measures it’s made good progress. Since the Integrated Pest Management Ordinance was introduced in 1996, chemical use has dropped 81 percent, according to the latest figures.
But there are still some areas — notable city-owned golf courses — that slurp up the bulk of the remaining chemicals. Of the 2228 pounds of pesticides and herbicides sprayed on city property last year, roughly 40 percent of it was applied to five public golf courses, most notably Harding Park Golf Course near Lake Merced. (There was no data available for the Crystal Springs Golf Course in San Mateo County).
The most hazardous pesticides — in the largest amounts — are used by city golf courses, especially Harding Park, according to a city pesticide use report. This is due to the “extraordinarily high cosmetic and playability requirements of international tournaments.”
“The lion’s share was used at Harding Park where the tournaments are held because of the high cosmetic standards,” said Chris Geiger, San Francisco’s green purchasing manager. “We have a contract with PGA tours and they send agronomists out on a regular basis to make suggestions, which are usually followed.”
A big bump in chemical use in 2005 was due to the American Express Golf Tournament at Harding Park. Last year, city-owned golf courses used eight pesticide products totaling 853 pounds (amounting to 236 pounds of active ingredients used). They included Roundup, Turflon Ester, Vanquish herbicide, Proturf K-O-G weed control, Cleary’s 3336 WP fungicide, Daconil, Primo WS B, and Sapphire.
Geiger said there’s little that can be done to avoid pesticide use on golf courses, unless you change the standards of the game. Clipping the green to 1/8 of an inch or shorter creates frequent open wounds for fungi to get in, he said, perpetuating the need for fungicides.
“It’s really a community discussion that should take place,” said Geiger about the heavy use of pesticides on golf courses. “There are those that value tournament golf for the economic benefits it brings and are willing to let pesticide use go forward. And there are those who want to see pesticide use cut no matter what.”
In 2009, the city switched to a less toxic herbicide to use on the course, but it required a dramatic increase in the overall amount applied. Similarly, city officials have been trying to switch to less toxic alternatives for other uses as well. But the spread of diseases like Sudden Oak Death have required more application of Agrifos, a phosphoric acid compound that boosts a tree’s natural immune response. The chemical is considered comparatively low toxic.
Another area of growth has been the use of public health insecticides, notably for mosquito control. Battling West Nile Virus in 2004, the city deployed a team of bicycle messengers to visit storm water drains to check for mosquito breeding sites. The city then dropped microbial pellets into the drains.
They’ve also noticed a correlation between the size of the city’s gardening staff and the amount of herbicides used. When gardening positions are cut, there’s a greater reliance on chemicals to do the work that gardeners do with their hands.