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Guerrilla Arborists Are Determined to Make S.F.’s Trees Grow Food

Fighting for fresh produce in the city, one tree at a time.


Frustrated by the dwindling availability of fresh produce in her neighborhood, Tara Hui takes matters into her own hands. At dusk, she hits the street armed with a knife, grafting tape or wax, rubbing alcohol, and a journal. In the shade of an ornamental tree, she drops her tools and surreptitiously saws off a low-hanging branch in a precise wedge cut. She pulls a small cherry-tree branch from her bag, lines it up just right, and joins it to the tree with tape or wax. A few years from now the limb and tree will have grown together, turning a sterile tree into a source of fresh fruit. Hui cleans her knife with rubbing alcohol, records the location in her journal, and leaves a small mark behind, a safe distance away: a stencil of a heart and branch, symbol of the Guerrilla Grafters.

“It started as an idea to plant new trees,” says urban gardener Hui, but government organizations balked at her public planting efforts. Then, at a permaculture guild in 2010, she met Margaretha Haughwout, an educator at California College of the Arts in Oakland. The pair formed the Guerrilla Grafters, a group of furtive fruit activists whose mission is to transform existing ornamental trees into fruit producers. “I was interested in what makes an urban agriculture project legal or not,” says Haughwout, a former volunteer at the Hayes Valley Farm. “Why are only some projects permitted?” 

For its part, the city is more concerned with a practical matter: the prospect of gooey, slippery dropped fruit gunking up sidewalks and streets. Carla Short, superintendent of San Francisco Public Works’ Bureau of Urban Forestry, calls the tree meddling a hazard. “Guerrilla grafting can damage the trees, or worse,” she says, and could result in a $1,847 fine—what it costs the city to plant and water a tree for three years. Though the Guerrilla Grafters have yet to be caught by law enforcement, they keep a low profile. The group maintains what they call an “on-the-ground trust network,” which entails a guarded list of the names of those involved and encrypted grafting data. 

Despite its under-the-radar operations, the grafting movement has garnered a following among urban designers, gardeners, and artists. Photos of the guerrilla grafts were shared at the 2012 Venice Biennale and Vancouver’s 2015 International Symposium on Electronic Art, where the group discreetly handed out free grafting kits, including a manual, tape, wax, and a heart-and-branch stencil that identifies the grafters’ work. Locally, they’ve created installations during San Francisco Open Studios.

In a collaboration with the organization Falling Fruit, the Guerrilla Grafters maintain an interactive online map that designates trees with potential for grafting. “We don’t disclose where the grafted trees are, for fear of vandalism,” Hui says, though grafted trees have been found in Hayes Valley and the Mission. To find the grafters at work, you’ll have to seek out one of the telltale stenciled branches dotting the city.


Originally published in the February issue of San Francisco 

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