Most Americans have never heard of permaculture. And although the approach is gaining traction among U.S. urbanites (full disclosure: I teach urban permaculture), ideas differ about exactly what it is. An environmental philosophy? An approach to ecological design? A particular set of farming practices?

Some new and beginning farmers are also becoming interested, as evidenced by a recent discussion on the role of permaculture in agriculture at a gathering organized by the California-based Farmer’s Guild—a network for “the new generation of sustainable agriculture.”

But is it a viable approach for farmers? Can it scale up in the context of the larger U.S. food system?

To permaculturists, the approach is much more than a synonym for sustainable agriculture. Speaking at the California Farmers Guild event, ecological landscaper Erik Ohlsen described permaculture as a way to create a “permanent culture” generally, applying it to food systems, but also to shelter, energy, and technology. This new culture, those like Ohlsen claim, can be consciously designed to meet human needs while respecting and regenerating the non-human environment, by following a set of nature-inspired “design principles.”

Bill Mollison developed the concept of permaculture and its principles in the 1970s, based largely on his studies of the practices of indigenous peoples. The principles include tenets like “use small and slow solutions,” “use and value diversity,” “creatively use and respond to change,” and “use and value renewable energies.”

Over its 40-year history, permaculture has spread as an evolving, experimental practice. The philosophy holds “earth care,” “people care,” and “returning the surplus,” as key defining ethics. The design process and strategies are taught through “Permaculture Design Certificate” (PDC) courses—an intensive 72-hour curriculum akin to an environmental science survey course.

The techniques, though, are what most people identify as permaculture. These include “food forests”—orchard-like systems of production with multiple layers of productive plants that emulate a forest ecology, “swales”—on-contour ditches dug to encourage rainfall to slow down, spread out, and sink into the soil, and “perennial polycultures”—planting plans for farms that encourage greater diversity than the monocultures of annual crops typified by modern industrial farms.

But permaculture doesn’t mandate exact techniques and forms of farming. Rafter Sass Ferguson, a researcher with the University of Lisbon who has studied permaculture farms in the U.S. and around the world, says that the 120+ farms he has corresponded with and visited for a recent study didn’t fit a set mold.

“[They] were incredibly diverse in their livelihoods, production systems, size and scale, age of the farm, age of the farmers, and so on,” Ferguson said. Though some of these farms used the formal permaculture design process, he noted that “many used the permaculture conceptual tools in a much more on-the-fly and ad-hoc way.”

The formal design process would start with site-specific information gathering and observation, and then use this data to inform design choices that produce yields while supporting the three ethics (“Earth care,” “people care,” and “returning the surplus.”)

Ad-hoc, though, is what Paul Oscar Hamilton, of Greenhearts Family Farm, prefers. He says he was inspired to become an organic farmer when he visited permaculture farms in New Zealand. But he farms like many organic farmers do, in “straight line row crops,” rather than following full permaculture design, because he says the incredible health of him soil allows him to.

Hamilton argues that permaculture is more difficult for many farmers to integrate than organic because “permaculture is slow and round.” The focus on perennials, for example, may take more time to get a production system going. In designing according to a farm site’s topography, permaculture might prefer on-contour planting to straight lines, which might make tractor work more challenging.