Inside the adobe home he built himself in Hepburn Springs, a spa town in the southern Australian state of Victoria, Mr. Holmgren, 63, is putting his words into practice.

Image Mr. Holmgren describes his newest book, “RetroSuburbia: The Downshifter’s Guide,” as part manual and part manifesto. Credit... Holmgren Design

“We need to bring power back to local areas and local people,” he said in March from his home, which sits on more than two acres, where he grows 200 different crops. “The pursuit of local food is central to that and always has been. Frugal hedonism is our approach.”

That approach is seen throughout his home. In a corner of his living room sit a spinning wheel, baskets of nuts and piles of corn and apples. Excluding rice, coconut cream and his favorite soy sauce, everything Mr. Holmgren eats is grown on the property.

The house, known as Melliodora — a local variety of eucalyptus — is powered by solar energy and cooled, he explained, through passive design, not air-conditioning.

Unshaven, his ponytail graying and the nails of his broad hands dark from work in his garden, Mr. Holmgren looks the part of pioneering environmentalist, who more than 30 years ago helped coin the term “permaculture” and found a movement.