All Tara Hui wanted to do was plant some pears and plums and cherries
for the residents of her sunny, working-class neighborhood, a place
with no grocery stores and limited access to fresh produce.

But
officials in this arboreally challenged city, which rose from beneath a
blanket of sand dunes, don’t allow fruit trees along San Francisco’s
sidewalks, fearing the mess, the rodents and the lawsuits that might
follow.

So
when a nonprofit planted a purple-leaf plum in front of Hui’s
Visitacion Valley bungalow 31/2 years ago — all flowers and no fruit, so
it was on San Francisco’s list of sanctioned species — the soft-spoken
41-year-old got out her grafting knife.

“I tried to advocate for
planting productive trees, making my neighborhood useful, so people
could have free access to at least fruit,” she said. “I just wasn’t
getting anywhere.”

Today, Hui is the force behind Guerrilla
Grafters, a renegade band of idealistic produce lovers who attach
fruit-growing branches to public trees in Bay Area cities (they are
loath to specify exactly where for fear of reprisal).

Their
handiwork currently is getting recognition in the 13th International
Architecture Biennale in Venice, Italy, as part of the U.S. exhibit
called “Spontaneous Interventions: Design Actions for the Common Good.”
Closer to home, however, municipal officials have denounced the group’s
efforts.

Even the urban agriculture movement is torn when it comes
to the secretive splicers, outliers in a nascent push to bring orchards
to America’s inner cities. While many applaud their civil disobedience,
others fear a backlash against community farming efforts. And few
believe their work will ever fill a fruit bowl.

Not that that really matters.

“It’s
like the gardener’s version of graffiti,” said Claire Napawan,
assistant professor of landscape architecture at UC Davis and a grafters
sympathizer. “Even if there’s some question about its ability to
produce enough food to make a difference … as an awareness piece, it’s a
good idea.”

On a sunny day toward the
end of summer, Hui was bent over an immature tree, searching for the
tell-tale strip of electrical tape that would show where a
fruit-producing branch had been spliced onto an ornamental plant.

The
small stand of cherry trees had been transformed during the most recent
grafting season, late winter to early spring, using a simple method
that Hui described as being “like tongue and groove in carpentry.”

First
a slit is made in the host tree. Then the alien branch is whittled into
a pointed wedge. The grafter inserts the wedge and matches up the
elements’ nutrient-transporting layers before securing the area with
tape. The Guerrilla Grafters use electrical tape instead of grafting
tape so they can color code their work for future reference.

“Once it heals, it connects,” Hui said. “Basically the branch becomes part of the tree.”

The
group only grafts trees that are nominated by a steward in the
neighborhood, who promises to maintain it and make sure that fruit is
harvested and does not become a hazard. Trees also are grafted within
species, fruit-bearing apple onto ornamental apple, for example.

If
all goes well, in several years grafted branches will blossom and bear
fruit. Of the 50 or so trees Guerrilla Grafters has transformed, Hui
said, a few already have produced fruit, including an Asian pear whose
location she would not disclose.

“Two months after we grafted it,
it flowered, and we went back again and saw little pears on it,” she
said. “Some passersby must have picked it and had it, which is the idea.
There’s no ownership of these trees. There’s just stewardship.”

The Guerrilla Grafters are as cagey about attracting members as they are about safeguarding the group’s operations. There is a Facebook page, and prospective grafters “contact us for the most part,” Hui said. “It’s a little tricky. We just want to be careful.”

It was a lesson learned the hard way.

On
Feb. 18, a grafting project was announced on Facebook: “Hayes Valley
Farm today at 1pm — Laguna b/w Fell and Oak.” Two days later, the
website said that “all the viable grafts on those trees were gone. …The
trees were so severely pruned, they even look kind of sad.”

The
group suspected city gardeners were behind the “vandalism” and beseeched
them to be kinder in the future: “Whether or not you agree with what we
do,” the post said, “please trust that we care about those street trees
as much as, if not more then you do.… We respect your hard work, please
allow greater participation in caring for our public space.”

Carla
Short, San Francisco’s urban forester, said that no one in the
Department of Public Works had “formally” removed any of the guerrilla
efforts performed by the group of 30 or so grafters.

If
the city’s tree crews come upon a grafting, they have been instructed
to report it to her, and “we’ll take it on a case-by-case basis.” Street
trees are allowed by permit only, and the city will not grant a permit
for an apple, plum, pear or any other fruit producer.

“We really
support growing fruit trees in the right places,” Short said. But “we
don’t want people to get hurt, and we don’t want to damage our already
vulnerable street trees.”

Community
gardens have prospered for decades on vacant lots in cities around the
country. But urban orchards — which require a greater investment,
particularly in time — have only begun to catch on in recent years.

That
commitment is part of the allure to the many romantics in the urban
orchard movement. If a tomato plant is a summer fling, they figure, then
a fruit tree is more like a marriage.

“You can have a
relationship over time with a tree,” said Lisa Gross, founder of the
Boston Tree Party, which has planted 110 apple trees in civic spaces
over the last year and a half and is planning its first harvest
celebration in 2015. “We all love tomatoes, but you put it in and pull
it out at the end of the season.”

Most urban orchards are created
with at least some municipal cooperation. The Philadelphia Orchard
Project, launched in 2007, has planted 449 fruit trees in partnership
with the city water department. The Beacon Food Forest, which will break
ground later this month, was developed on seven downtown acres owned by
Seattle Public Utilities.

And Fallen Fruit, an art collective,
has plans to create Los Angeles County’s first “public fruit park” — 100
trees planted in and around Del Aire Park near Hawthorne. Like the
Guerrilla Grafters, the folks at Fallen Fruit say future harvests would
be there for anyone who wanted them.

Ornamental street trees that
are not bearing fruit “should be abolished,” said David Burns, who
co-founded Fallen Fruit and is working on the park project with the L.A.
County Arts Commission. “That should be just not legal.”

In a
South of Market conference room, four members of the Guerrilla Grafters
hunched over their laptops, working on the next phase of their sweetly
subversive project.

Using data available online, they hope to
pinpoint every one of the approximately 103,000 street trees in San
Francisco that might be turned into a fruit producer. They also plan to
map every grafted tree to aid in care, future harvesting and research
into which species work best in the city’s varied microclimates.

The
prototype maps look like abstract watercolors, and the database lists
each tree’s location by latitude and longitude, as well as its
scientific and common names. For a select few, there is a notation about
what was grafted on and when.

After a decade working in high-tech, software developer Jesse Bounds,
35, took a year off and traveled the world with his wife. They
volunteered on a vineyard in Italy, helped create water filters and
stoves for South American villagers and lent a hand to Elephant Human
Relations Aid in Namibia.

To Bounds, who has also grafted with the
guerrilla group, the database is “software development work with a
clear connection to the real world.”

Hui also was trained as a
computer scientist, but left the industry years ago to dedicate herself
to the causes that she said matter: social justice, sustainability and
community.

Her day job is with a nonprofit organization called
Kids in Parks, where she teaches outdoor science classes to
middle-schoolers on a part-time basis. With the help of a friend, she
designed and built the Poo Garden, a prototype composting toilet that,
when full, becomes a planter.

Hui said she works hard “to be less
dependent on money.” She barters and trades with friends. She keeps
backyard chickens and eats from her home vegetable garden.

She dreams of cities filled with fruit trees.