“Feed the soil, not the plant!” speaker Chris Jackson advised the audience that filled the Hapgood Room for his talk on “Permaculture Gardening” Thursday, January 11.

Jackson explained that permaculture, a word originally coined from “permanent agriculture,” has grown to mean design systems that use nature as models to meet human needs. Rather than a method of cultivation, permaculture is a way to think about how nature solves a problem. It emphasizes thinking about plants, animals, and other elements of a garden as multi-functioning components of a healthy ecosystem, rather than as single food sources.

According to Jackson, permaculture is also an ethical system based on care of the earth, care of people, and setting limits on consumption that allow us to realize the first two goals. Taking cues from the ecosystems, permaculture design recognizes that plants and animals bring more than one function to the garden. For example, a climbing bean can provide shade and add nitrogen to the soil, as well as produce beans.

Like nature, permaculture advocates diversity, with an emphasis on the number of beneficial connections among components, rather than the number of diverse things. When all goes well, permaculture design should promote gardens that are productive, yet require less work and are more self-sustaining than traditional gardens.

“Start at your door,” Jackson suggested. Grow herbs, greens, and other plants that are picked frequently as close to the house as possible. In addition, he recommended diversity and companion planting to minimize pests and improve the soil, reduce weeds, retain moisture, and add nutrients.

Jackson passed on some tips from his current work restoring a neglected apple orchard. “Grass is the enemy of trees,” he said. “It competes with the surface roots for nutrients.” Instead, he recommended introducing plants that will support the tree’s needs, such as flowers that attract pollinators, plants that fix nitrogen in the soil, and dynamic accumulators like Russian comfrey, with roots that go deep in the soil and pull nutrients up into the leaves. The nutrients then replenish the topsoil when the plant dies back.

For the home gardener, Jackson advised seeking out disease-resistant heirlooms and trying less well known fruits and nuts that are not as prone to pests and diseases as modern apples.

Jackson, a Bromfield graduate, is the son of Kathy and Pete Jackson of Jacob Gates Road, whom he credits with fostering his interest in farming. His work has taken him from Vermont to Mexico and back. The Garden Club and Harvard Local jointly sponsored his presentation.