The flower-shop owner Patrick McCann at Wednesday’s rally. PHOTOGRAPH BY VAUHINI VARA

On Wednesday, tenants of the San Francisco Flower Mart gathered at a stall run by a flower grower named David Repetto, to rally against what they see as the tech industry’s latest incursion into traditional San Francisco. The affront took the form of a planned acquisition of their building, for twenty-seven million dollars, by the real-estate firm Kilroy Realty. The location that has held the Flower Mart since the nineteen-fifties is largely owned, for now, by the San Francisco Flower Growers Association. But the Growers’ board, looking to do right by its shareholders and to give them some liquidity, has agreed to a deal with Kilroy that would result in the association’s part of the site being moved under Kilroy’s ownership. And the California Flower Market, which owns another big portion of the site, has said that it is also negotiating with a developer—possibly Kilroy, though no one will say for sure.

The Flower Mart, the second-largest wholesale flower market in the country, is a San Francisco institution; Martha Stewart once said that she found the most beautiful hydrangeas there. It is a huge space in a city of small spaces; growers arrive in the early, dark hours of the morning with dahlias and marigolds by the bucketful. Repetto, who runs a nursery in Half Moon Bay, southwest of the city, remembers going there with his father when he was a child. Back then, he said, growers would enter the buildings with their cars and sell their flowers from the bed of their trucks; now, more than sixty growers and wholesalers lease sections of the warehouse that florists can visit. The tenants want an assurance that they'll be able to stay after Kilroy acquires the site. Repetto had cleared off one of the carts that he uses to bring flowers in and out. Someone had placed a couple of bunches of dahlias on either side; in the center lay a bouquet of TV crews’ microphones. In the audience, some women waved signs: FLOWER POWER, PEOPLE OVER PROFITS.

Patrick McCann, who owns a shop in the Flower Mart called Greenworks and organized the event, trotted out speakers—a florist in his nineties, Al Nalbandian (“This is the second home of our families”); Repetto himself (“Uh, I think we just all have to band together here, all for one, one for all”); a former mayor, Art Agnos (“I first came to the city in 1966, and that was the era of the flower child and flower power”); a retired state senator and city supervisor, Quentin Kopp (“I founded the flower caucus in the state legislature”).

Jane Kim, a city supervisor and, apparently, the only politician in the room who currently holds office, moved to the microphones. Kim represents the South of Market neighborhood, where the Flower Mart sits; she is best known, lately, for pushing for more affordable housing in the city, but she also helped to pass a controversial tax break for San Francisco tech companies. She wore a dress with a tropical-flower pattern and said, diplomatically, “It’s really important, I think, for a city to support change. I think change can be positive.” The city should also, however, protect its institutions, she added.

A woman in the audience muttered, “We don’t want change. Do we want change? We don’t want change.”

This is a common refrain in San Francisco these days, with the tech boom having rapidly transformed the city—and the SoMa neighborhood in particular. Airbnb’s headquarters are two blocks from the Flower Mart; Twitter, Uber, Square, and Yelp aren’t far, either. The city is constructing a light-rail line that will connect this area with downtown and Chinatown. In conjunction with that project, local politicians and policymakers are rezoning the neighborhood. Historically, there were a lot of warehouses here. Now, tech companies want to move into the space—some of which sits empty or unused—but many of the sites are still zoned for industrial use.

The expected rezoning seems to have been crucial for Kilroy. After the rezoning, Kim told me, much of the space will be converted into office or residential space; in a call with investors in late July, John Kilroy, the C.E.O. of Kilroy, called the Flower Mart acquisition “a tremendous office-development opportunity.” Kim’s main goal is to make sure that much of the area is preserved for affordable housing; whether the Flower Mart should stay in its current spot, she said, depends on whether this is truly the right neighborhood for it, and, of course, whether the tenants want to stay there. While some policymakers in the city feel that SoMa doesn't have much use for warehousers and wholesalers these days, Kim wants the rezoning plan to preserve some sites for those uses. Maybe the flower venders would rather be in the Bayview neighborhood, where the city has its produce market, she said.* “But, from my basic understanding, which is that this is a viable site, they’re doing well, and this is the space they want to be in then. I would want to support that,” she added. (Kim and other supervisors will be involved in the planning process, and their consensus on the Flower Mart could well influence what happens to it.)

For years, it made little sense for developers to try to buy the Flower Mart; like other buildings in the neighborhood, it was zoned to be used for “production, distribution, and repair.” But, after the city’s rezoning plans got underway, Kilroy, in 2013, started talking with the San Francisco Flower Growers Association. (The general manager of the association, Ronald Chiappari, declined to comment.) In July, the board approved a merger that will result in Kilroy owning the association's portion of the Flower Mart.

The Flower Mart’s tenants are suspicious of Kilroy because it so often buys buildings and turns them into offices for tech firms, but Kilroy insists it doesn’t plan to kill the Flower Mart. Tyler Rose, its chief financial officer, read me a statement noting that Kilroy “remains committed to working with adjacent owners, existing tenants, and the city to preserve the Flower Mart at its current location.” He added, “After we acquire the site from the San Francisco Flower Growers Association, we look forward to conducting an extensive outreach and planning process to create a modern facility to be enjoyed by growers, tenants, buyers, and visitors for many decades to come.”

At Wednesday's rally, Repetto wore a John Deere cap, a Ben Davis work shirt, and an amused expression. He was surprised, and glad, to see the event get so much attention, he said. Repetto sells at least half of his flowers at the Flower Mart, he said, and he’s not sure what he would do if it disappears, or if it moves elsewhere. He used to ship to buyers in New York and New Jersey, but, over the past couple of decades, South American growers have been taking business from him. We stood among buckets of flowering kale, dahlias, and amaranth. He would like to stay put in the building, he said, but he knows that the owners are free to do whatever they like. “Money runs everything,” he said.

*Update: This post has been changed to note that Kim believes that the city's rezoning plan should preserve some sites to be used by warehousers and wholesalers.