WHEN I HEARD that today’s guest, who’s been a guiding force in educating organic farmers, was finally publishing a book specifically for gardeners, I was thrilled. I’d been following Jean-Martin Fortier since his first handbook on biointensive organic market farming came out more than a decade ago, and even gone to hear him speak at farming conferences—then done my best to translate and distill his advice and apply it to my own garden size and conditions. Now JM, as...