(Whether you’re starting your first garden or switching to organic, Rodale’s Basic Organic Gardening has all the answers and advice you need—get your copy today.)

Then Thomas, long dreads framing a smile, told a story of her own. She showed a portrait of Harriet Tubman. “She was born onto a homesteading farm, and it was only her relationship with the forest that enabled her to design the path that she needed to help get African-Americans who were enslaved to freedom,” Thomas explained.

For her mostly white audience, the example was a reminder of the “green” roots of black culture. It also illustrated how a deep relationship with nature can be a tool of radical social change. That notion is core to the work of Thomas, who at 45, is one of the most important voices in the world of permaculture. She takes a discipline conceived for farming and brings its concepts into her community-building work in largely urban settings.

Devised in the 1970s by Australian biologists Bill Mollinson and David Holmgren, permaculture is agricultural and social design that mimics nature. Permaculturists create closed-loop systems modeled after ecosystems. Using a set of progressive ideals—small, slow solutions; recycled resources; valuing diversity; staying open to changes and responding creatively—they seek to minimize their impact on the earth while maximizing their yields. The discipline has its origins in farming: Biodynamics (which treats the farm holistically, as a ecosystem), and aquaponics (which uses fish to fertilize plants and vice versa) are examples of permacultural practices.

But it’s not just useful for cultivating plants. Thomas, who calls herself a “social permaculturist,” is on the vanguard of a growing movement that uses permacultural principles to promote social justice. “Permaculture has focused so much on land, but people are a part of that system,” Thomas said over a lunch of bone broth and raw beet salad at the organic restaurant Mission Heirloom in Berkeley, California, near her home. “We need to heal people and relationships just like we heal the soil.”

Key to that healing is “meeting people where they’re at,” she says, “so they don’t have to become some new person to live this organic life.”

Educated at Tufts University in green building and city planning, and schooled in permaculture on the job as a farmer and at various non-profits, Thomas is an innovator of programs that reach urban communities of color: Grind for the Green, a concert series that used hip-hop to promote sustainability practices; the Black Permaculture Network, which supports organic African-American farmers; the Toyota Green Initiative that brought black celebrities to college campuses to promote environmentalism. These projects have targeted a population that green activists have long seen as lacking in eco-friendliness—a stereotype that Thomas rejects. People of all kinds “want connection to the earth, and they want meaning and they want community,” she says.

“Traditional environmental work doesn’t take a lot of people’s experiences into consideration. Part of my work is how to be a bridge.”

It’s work that was inspired early on by her mother, Francis Thomas, a South Carolina sharecropper who moved north to Farrell, a town surrounded by Amish farmland in western Pennsylvania, during the Great Migration. “She still had that connection to the earth,” says Thomas. “She was an avid gardener.” The family’s living room “looked like a jungle.”

Life, though, in Farrell was tough. The steel mill where Thomas’ father worked shuttered in her youth, leaving a polluted local river and high rates of unemployment in its wake. The fallout made a deep impression on Thomas. She watched family members and neighbors fall victim to cycles of poverty and incarceration. “I was very aware of unfairness and injustice. There weren’t many jobs. There wasn’t access. There was just trauma.”

Thomas herself had a chance to escape that trauma during high school when she went to live in Germany for a year with her older sister, who was in the Army. “My mother never traveled out of the country. We didn’t have a lot of money,” she says, “but she got me on that plane. It was a powerful gift for me to see the rest of the world.”

She returned to Farrell intent on wanting to “understand my place on the planet,” she says. She enrolled in the local college where she also got involved in the environmental activism that made her an outlier. “My environmental friends in college had this perception that black people didn’t care about the environment.

“And students in the African-American union called me a hippie, saying I only cared about polar bears and recycling.”

But, for Thomas, what had happened to the natural and social worlds of her town couldn’t be separated.

“I saw a connection between the environmental impact we were discussing in groups at school and the African-American organization boycotting a prison across the street from my university.” A sophomore year abroad in Nepal only reinforced those connections: “The Tibetan people had been misplaced and were trying to keep traditions, many rooted in the earth, alive.”

At Tufts, where Thomas transferred to finish college, she sought to combine environmental and community activism, becoming enamored of green building and writing a young-adult manual on the subject called Shades of Green, for the non-profit organization YouthBuild. But the world of LEED certifications and sustainable architecture proved too corporate for Thomas.

So she turned instead to permaculture, spending a stint in Venezuela farming before she landed a job at Global Exchange in San Francisco, bringing permaculture education into inner-city high schools. At Global Exchange, Thomas worked alongside artist Zakiya Harris, and in 2010, the co-workers started their own firm, Earthseed Consulting, to help companies and organizations reach black communities with their pro-planet messages. Together, they developed the Toyota Green Initiative, a first of its kind campaign targeting African Americans and educating them on the benefits of adopting a sustainable lifestyle. For six years, they helped to lead the automobile company’s marketing on environmentalism among African-American college students. They helped to launch a roadshow that included workshops in making DIY organic cleaning and beauty products, culturally relevant performances, talks, and eco-goods giveaways, all designed by Earthseed Consulting.

“You meet people where they’re at,” Thomas says. “We’d do a 20-minute demo with some famous person. We made an air freshener, a house cleaner, and a facial scrub. We put together a list of eight ‘have to have’s’ in our tool kit.” Lemon, white vinegar, baking soda—“these are things that all our families have had in their cupboards for years, so we were reintroducing the concept that sustainability is something in our own homes.” Earthseed’s programs made going green relevant to their audience.

When the Toyota contract ended, Thomas returned to one of the issues that had first galvanized her: the widespread incarceration of the black community. She had been volunteer-teaching environmental literacy at San Quentin Prison. “These men were passionate about sustainability,” she says. “Just because someone’s incarcerated doesn’t mean they aren’t avid about the issues.”

Her students told her that they needed help getting back on their feet once when they were on the outside. So Thomas co-founded Pathways 2 Resilience, an 18-month permaculture and social entrepreneurship training program for former prisoners Services-rich, it embodied the permacultural principle of stacked functions. “It had to be a case management program. It had to be healing and provide a stipend. We had to feed them. We had to wrap all these into the same experience.”

It began with something that Thomas calls “the Mandela Welcome,” after anti-apartheid activist Nelson Mandela, who spent 27 years as a political prisoner before returning to become the first president of a democratic South Africa. “Permaculture has this principle that says the problem is the solution,” explains Thomas.

“All these men and women coming home from prison, we see them as a resource.”

Though the grant for the program eventually ran out, Pathways 2 Resilience had impressive results. All 13 participants graduated, and all but one have remained free of new convictions. The project Thomas is currently working on, pushes the problem-as-solution concept further. Called Women Designing Resilience, she’s co-designing it with one of Pathways to Resilience’s graduates, Linda Candelaria. Permaculture design, therapeutic circles, social entrepreneur training, small business start-up grants—they will plan all of it with an eye toward empowering these ex-inmates to become leaders in their own right.

That’s not unlike the organic farmer who works with, rather than tries to control, the natural cycles of her land. The way Thomas sees it, her work might not involve seed saving or composting, but nonetheless, it’s permaculture. As she puts it, “I think my farm is wherever there’s people. I think I’m growing people.”

Keep up with Pandora Thomas and her work at PandoraThomas.com