Five days after Christmas, Tommy Joshua received an e-mail from a Philadelphia Housing Authority official that threatened to bulldoze the preceding three years of his life. The agency would be testing soil on land it owned in Sharswood, a neighborhood defined by its two 18-story project towers and the expanse of vacant land that surrounds them.

Joshua put on his boots. With a dozen neighbors Jan. 6, he walked five blocks to prevent the PHA from digging into its own property at 24th and Bolton Streets, once an eyesore and now something promising, named North Philly Peace Park.

One of the protesters wrote on a cardboard sign: "Shame on PHA!"

Housing workers were to drill in the center of the garden and see if the earth could support a building foundation; the first redevelopment of the barren area is planned for the heart of the park.

Joshua, 35, a Temple University graduate, and a third-generation Sharswood resident, had helped revive the lot in 2012. Volunteers cleared car parts, dirty diapers, and syringes. They planted heirloom tomatoes, cauliflower, and squash. They built a hut using recycled materials and created a place where farming and nutrition classes were taught. Last September, they held the neighborhood's first urban county fair.

Joshua believed the city-owned land was a hazard. Someone had to reclaim it. Someone had to defend it. His group told the city workers they could not start their sampling.

For 15 minutes, the two groups stood their ground, until PHA officials arrived and negotiated a truce.

"I knew PHA wanted to test us," Joshua said. "They wanted to test our resolve."

Kelvin Jeremiah understands the skepticism. The PHA president anticipates it will linger until the Blumberg towers, which occupy eight acres two miles north of City Hall, crumble this fall.

For decades, the agency has promised change to one of the city's poorest neighborhoods. Nearly 1,400 vacant buildings and lots - the equivalent of 26 football fields - cripple the area.

"I would be the first to concede PHA, as an organization, has not always been the best neighbor or the best partner," Jeremiah said. "That is fundamentally among the things I would like to change."

The neighbors see the development to the west in Brewerytown, to the south in Fairmount and Francisville, and to the east at Temple University. Sharswood, they hope, can benefit.

The PHA wants to be the agent of this change. It has allocated millions in funds for building new homes. It organized countless community meetings in the last year and stressed that displaced residents can find permanent homes in the area. It wants to work with the few existing institutions in Sharswood.

The Peace Park is one of those, and the PHA controls its fate. The garden will be uprooted in June, when ground is broken on the first phase of redevelopment, 57 rental units on 24th Street.

"Obviously something is working here," Joshua said. "Why not work with us to develop the neighborhood?"

Jeremiah, like Joshua, views this as a test. He promised better community interaction, and he said his staff would work to find another location for the garden. There is nothing in writing.

The park is an oasis for the residents of the Blumberg senior building, across the street from the Peace Park. There are no fences; people are free to pluck crops whenever they like. The closest grocery store is nine blocks away, on Temple's campus.

Leroy Smith, 79, pointed his motorized scooter across 24th last weekend. He puffed a cigarette as he watched people clean the garden for the coming spring, and nodded proudly. Smith comes for tomatoes and collard greens.

"This would be a big loss," he said. "This would really be a big loss."

Amia Jackson paced the garden beds last weekend with Joshua and made a list in her spiral notebook. Jackson, 26, is an LSAT instructor who lives in Brewerytown. In her spare time, she is the Peace Park's farm coordinator.

"The okra did amazing for us," she said. "People love the okra."

T.J. Lawrence, a 15-year-old apprentice who lives at Blumberg and is learning to farm, scoffed.

"Okra is disgusting," Lawrence said.

Jackson laughed and said, "You don't have to eat it, T.J."

The Peace Park crew tilled the land three years ago. It imported compost to improve the soil, which is pocked in some spots with bricks from houses long destroyed.

The seeds are donated, the equipment is borrowed, the labor is free.

Last season produced the park's best harvest.

"People have put so much work in on the land here," said Eli Schewel, an arborist who has planted 12 trees at the Peace Park.

Dan O'Brien, an assistant managing director for the city who oversees a neighborhood outreach program called PhillyRising, marveled last summer at the Peace Park's space. "Sometimes," O'Brien said, "we make things more complicated than we should." His hope is for it to survive.

Joshua is willing to relocate the park - with a written guarantee of land.

"We feel the same way PHA feels," Joshua said. "That's the issue. We see ourselves as responsible citizen urban planners. I'm committed to seeing justice in this neighborhood. We're talking about a really suppressed neighborhood. Generational poverty. Institutional neglect. No supermarkets, no schools.

"There is a lot at stake."

The last communication between the sides was the soil-test e-mail and the ensuing staredown. For Joshua, the silence is unsettling. It's time to plant, and the garden could be disrupted without notice.

Jackson, the farm coordinator, is four months pregnant. Her thoughts last weekend turned to one of her favorite images from the summer.

"Kids eating kale," Jackson said. She smiled.