Permaculture is gardening by using a variety of strategies to create groupings of plants that support each other and the soil over an extended period of time. The strategies include choosing plants that serve multiple purposes at once. For example, a small tree might provide shade for shrubs that need protection from the broiling sun to get started, pull nitrogen to the surface where it is more readily available for use by other plants, and drop leaves in the fall that serve as mulch to keep down weeds and to add organic matter to the soil. Permaculture evolves from young, immature plantings to forests over a course of decades; the permaculturist focuses on trees and perennial shrubs rather than on annuals and on building the soil in place rather than by adding materials from outside the loop.
The book is a great introduction to the discipline and gives lots of starting points for the home gardener. Will I forego my vegetables for guilds focused around black walnuts? Not tomorrow and probably never completely. Will I ask Love to build a series of ponds to filter our graywater and provide habitat for ducks to keep the insect population of The Realm in check? Not next week. Will I gradually incorporate some of the techniques and ideas Hemenway posits? Absolutely. Take those heritage apples I've been thinking of putting in to expand our apple harvest. I now plan to use each of those as the centerpiece of a guild. I'm also going to chunk the woodlot and approach each section with a critical eye as to what plants to encourage, which ones I should eliminate (or move), and what plants I should add to help move our overgrown yard toward an edible forest.
My favorite quote from the book: “Doing an imperfect something is better than doing a perfect nothing.” Amen, brother!