Articles

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IPM is a multifaceted strategy that aims to reduce herbicide and pesticide use by first turning to biological, cultural and mechanical techniques to control environmental problems. Only as a last resort will IPM practitioners turn to chemicals. And the city mandate requires that when chemicals are used, they are the least toxic possible.

This blanket ordinance covers everything the city owns, from Muni buses (cockroaches!) to City Hall, and from tiny neighborhood rec centers to Golden Gate Park. Since its inception, the city has seen an 86 percent decrease in its use of herbicides, and application of toxic pesticides has dropped by over one-half.

This is a dramatic change for the Parks and Recreation Department, whose previous response strategy relied on literally tons of suspected carcinogens to control weeds, lawn diseases and pests. Five years later, the department's IPM program is a national model, and Phil Rossi, the Parks and Rec IPM coordinator, regularly receives calls for advice on weed and pest control from other municipalities.

While the techniques are equally practical for the home gardener (we'll get to some of them below), I can't help but marvel at the mental shift made by the more than 350 gardeners who care for over 3,000 acres of city parks and golf courses. Yeah, yeah, change is good, but who really embraces change, especially at work? I can only imagine the grumbling that must have gone on at some of the early IPM meetings, back when pesticides were among the department's primary tools.

Rossi, who was not yet with Parks and Rec when the IPM program went into effect, says there was indeed lively discourse from some folks initially, but the gardeners are now wholeheartedly into the approach. They were quick to see that not only would the picnicking public benefit from the new strategy, the staff now had a markedly healthier, safer work environment.

Rossi adds that for all of us, who live in a throwaway culture and are subject to expensive ad campaigns from big chemical corporations, the IPM approach does take a paradigm shift; practitioners need to be tolerant, patient and committed.

Weeds Beware

So what is the Parks and Rec Department doing that's so different? First of all, its method for tackling weeds, which had previously employed herbicides exclusively, now involves a multipronged, multistaged approach. Today, weed control generally includes using thick layers of mulch to inhibit weed growth. Plants are also covered with weed cloths, which block sunlight from getting to weed seeds and make it difficult for those that do germinate to penetrate the weed cloth.

Additionally, gardeners use handheld flamers, which resemble welding torches, to "cook" weeds and their seeds, preventing them from germinating. And if there's a crack in the sidewalk where weeds repeatedly spring, it is repaired.

In the past, since the Parks and Rec lawn mowers could not get close enough to a fence line to cut the weeds growing there, gardeners used herbicides. Now, fences are built on a low concrete strip that a mower's wheels can roll over, allowing the blade to get at the weeds.

When it comes to treating bugs, the staff focus on improving soil health so plants will be healthier and better able to avoid an infestation. To fight aphids at the rose garden in Golden Gate Park, for example, Rossi says they're using vermiculture compost (worm poop) combined with vermiculite, a mined substance that improves the ion exchange between plants and soil. This combination generates an enzyme reaction in the roses that creates a shield on the leaves, making it more difficult for aphids to eat the foliage.

To combat snails, the gardeners are working with an iron phosphate-based product called Sluggo that's applied like typical snail bait, but rather than depositing toxic metaldehyde in the soil, it leaves valuable phosphate, essential to plant growth.

Pesticide Pits

Historically, golf courses have been soaked in pesticides. Turf is constantly under stress when it's cut as closely as it is for the putting greens, which makes the grass highly vulnerable to fungus-based disease, and almost all golf courses are treated with chemicals on a regular preventive schedule. That means they're getting sprayed whether disease is present or not.

But the City is following the lead of the Presidio's Marnie Blair, who treats the Presidio golf course with a regular dosing of compost "tea." The mixture, filled with fungus-fighting microbes, keeps the greens looking sharp.

Blair, who runs an outstanding composting program at the Presidio, donates some of her yield to the Parks and Rec Department, which uses two 100-gallon brewers for making its own compost tea.

Rossi says that because of this program, no fungicides have been used at either Lincoln Park Golf Course or Pacifica's Sharp Park Golf Course for the past three months, and the greens look terrific. This approach is a big first step in golf-course maintenance, and Rossi adds that he wants to have a brewer at every municipal course.

Rossi and his colleagues are always on the lookout for new techniques and products they can implement. Right now, they're experimenting with putting dyes in our local ponds to mask ultraviolet rays, thereby preventing algae from blooming. The S.F. Parks and Rec Department is the vanguard for implementing an urban IPM program on such a large scale, and I say, go on, Parks and Rec!