Restoring Natural Areas in San Francisco
Historical Essay
by David D. Schmidt, 2026
An excerpt from the book, San Francisco Bay Area: An Environmental History, by David D. Schmidt (Backcountry Press, 2025).
Bernal Heights in 2022, after decades of work to re-establish native plants and to reduce the presence of invasive species.
Photo: Chris Carlsson
Of all the Bay Area counties, San Francisco has the least remaining habitat for native plants and wildlife, though it still has an amazingly diverse 509 species of indigenous plants—down from 766 in the late 1800s.(1) In 1974, recognizing the city's last chance to save dwindling fragments of undeveloped land, the Board of Supervisors placed Proposition J on the ballot, to create an Open Space Fund for buying these properties and preserving them as city parks. These grassy hillsides and hilltops were already being used as parks by local residents, who were often shocked and upset when developers showed up with bulldozers to begin construction. City voters approved Proposition J and its successor, Proposition E in 1988, to renew the fund.
After acquiring these lands, however, the city's Recreation and Park Department did nothing with them—not even picking up trash. Neighbors such as California Native Plant Society (CNPS) members Roland and Barbara Pitschel began to pick up litter regularly on Bernal Hill in 1986. They noticed that invasive weeds like wild radish and fennel were threatening the small remnant native plant areas on the hill, so they began pulling these weeds, too. Jake Sigg, leader of the Yerba Buena (San Francisco) CNPS chapter, saw that invasive French broom was spreading over the grasslands of Twin Peaks and Mount Davidson, two of the city's biggest native plant habitats, so in 1988 he asked the parks department for permission to start removing it from these and other natural areas in the city’s parks. Sigg recruited another CNPS volunteer, Greg Gaar, and started weekly broom-pulling sessions.
Throughout San Francisco’s 31 natural areas, the remnant patches of native plants were shrinking before advancing thickets of French broom, radish, and other invasive weeds. Removing them was far too big a job for two volunteers, so Sigg and local CNPS members pleaded with the city's park managers to assign staff to care for the natural areas. Park planner Deborah Learner drafted a management plan in 1995, and the parks department in 1997 began hiring a crew of eight to carry it out.
These eight, the park department’s Natural Resources Division (NRD), have been working with Sigg, CNPS and other volunteers for more than 25 years at 31 natural areas throughout the city, including the native live oak forest in Golden Gate Park’s northeast corner. The NRD also grows native plant seedlings, and plants them by the thousands each year in areas cleared of invasive weeds. Among NRD’s biggest successes was the restoration of riparian habitat in Glen Park along the city’s last remaining stretch of natural creek (outside the Presidio), in the late 1990s and 2000s. There, they removed English ivy and reintroduced Scarlet monkeyflower in the creekbed, which had been extirpated from San Francisco in the late 1800s.
Islais Creek running through Glen Canyon, 2013.
Photo: Chris Carlsson
In the early 2000s an overzealous volunteer girdled several Eucalyptus trees on Bayview Hill and Mount Davidson, provoking intense opposition from neighbors. The parks department promised not to remove large trees without community input, and commissioned detailed restoration plans for each natural area, balancing existing park uses with native plant restoration. The plans were released, and public hearings held in 2005.
Through several years of turmoil, the NRD and CNPS volunteers persevered, pushing back the tide of invasive plants and convincing even some of their detractors that native plant restoration, by removing dense thickets of invasive weeds, increases usable parkland for everyone.
Questions? Email the author: davidnaturesf@gmail.com
Notes
1. Wood, Michael, Annotated Checklist of the Vascular Plants of San Francisco, Third Edition (San Francisco: California Native Plant Society, Yerba Buena Chapter, April 2022), 7.
Excerpted from David D. Schmidt's San Francisco Bay Area: An Environmental History. Available from Backcountry Press.