Urban farms are becoming an integral part of Detroit's landscape. (Photo by Urban Roots Film; click to enlarge.)

What happens to a post-industrial city? How does it revive itself amidst the ruins of a disappearing way of life? In Detroit, modern America’s favorite example of urban decay, the auto industry left behind pockets of resilience: “Growtown” is full of urban farms flourishing inbackyards and abandoned lots, like wildflowers sprouting from the ash of a charred forest.

Detroiters have practiced urban agriculture for decades, but the city’s economic decline — which has been dragging on since long before the worldwide financial collapse in 2008 — serves as a catalyst for gardening’s explosive growth in this town that most of the country still sees as a poster child for inner-city ruin.

Urban Roots, a documentary playing at the San Francisco Green Film Festival on Tuesday, shows us a different image of the city through the eyes of its dedicated urban farmers. In addition to giving background on Motor City’s rise and fall, and introducing viewers to the folks behind a handful of urban farms across town, the film digs into important topics like the racial implications of gardening. Despite its negative associations with slavery, the film argues, working the land can be a powerful vehicle of self-determination and empowerment for Black Americans — especially in a long-neglected city like Detroit, where residents have learned the hard way not to expect change from above.

“Detroiters do not wait for handouts,” says filmmaker Mark MacInnis. (He has deep roots in the city: He grew up there, his mother worked in the auto industry, and his grandfather and great-uncles owned an asphalt company that paved most of Detroit’s roads.) “They know how to survive.”

It makes sense, then, that many of those still surviving in this city — which has lost a quarter of its population in the last decade — would have a knack for growing things. Providing your own basic sustenance is just about the most concrete way imaginable to regain a sense of control over your life. And gardening has positive psychological as well as practical benefits. “When you grow something and you nurture it, it spiritually awakens something within you,” MacInnis says.

All the empty land in Detroit makes it a place physically suited to an urban farming revolution. The island of Manhattan, plus the entire cities of Boston and San Francisco, could fit within Detroit’s borders, and the vacant lots on many blocks offer ample unused space. Some gardeners work their own land, some have adopted lots through the city, and some land-use agreements, MacInnis says, “are just based on a handshake … a lot of people don’t understand how that works anymore.”

A young Detroit gardener shows off the results of her hard work. (Photo by Urban Roots Films.)

Urban Roots, which looks like it was shot mainly during the summer, makes the city look pleasantly pastoral. With vegetable plots, fruit trees, and chickens wandering around, it’s a far cry from the ruin porn we so often see of Detroit. The film delivers the requisite tracking shots of house after dilapidated house, but answers them with aerials showing how green space is slowly taking back this most industrial of cities. The prevalence of growth is evident on the ground, too: At one point, an urban farmer takes us on a walk around his neighborhood to point out the several different households keeping chickens, raising goats, or growing collard greens and other vegetables, all within a few blocks of his farm.

Says MacInnis: “Once you teach somebody how to farm or grow food, the neighbors learn; it breaks down barriers and brings communities together.”

Urban Roots conveys an infectious energy spreading throughout the city, garden by garden, that is palpable even to faraway viewers. While I was watching it, a couple friends stopped by and, intrigued, quipped: “We have to move to Detroit and start gardening!” While there’s definitely a growing contingent of people acting on such an urge, the film dispelled my misconception that urban farming in Detroit is being driven by white hipsters moving in to capitalize on a trend.

Most of the farmers featured in Urban Roots are diehard Detroit natives, black and white, but, as MacInnis says, most are “extremely open to sharing their knowledge with other farmers moving in who seek out help.” Tension comes less from individual, community-minded newcomers than from those with a corporate vision for Detroit’s empty land, such as Hantz Farm. “If you’re somebody with deep pockets, and you’re trying to take over extreme amounts of land, and you come in and don’t introduce yourself to the community, that’s going to cause tension,” says MacInnis.

MacInnis talks excitedly of a creative renaissance that’s about much more than just gardening: “Things are happening in that city, with urban farming and the music and the art that comes out of there, that most of the U.S. hasn’t seen before,” he says. “Urban farmers don’t want Detroit to come back and be all urban farms. They want to farm and be able to go to a concert.”