Pollan is both writer and participant in this tale. In each chapter, he writes about his own discoveries as a gardener, and he uses his garden as a microcosm of the larger trends he discusses. For example, in the chapter on the potato, he writes about his own experiences growing genetically engineered NewLeaf potatoes. He also visits potato farmers in the Midwest who grow potatoes on a larger scale, but he keeps returning to the growth of his own potatoes and his reflections on growing them as part of the larger story.

John Chapman, also known as Johnny Appleseed, is a central character in the first chapter. Pollan attempts to unearth the real man behind this now Disney-ified character, and Pollan believes that Chapman was much more complex than the myths that have been passed down to us convey. For example, Chapman was not only a religious figure who believed the afterlife was prefigured in what occurs on earth (a philosophy called Swedenborgianism), but he was also a man who liked to drink and who brought seeds to settlers eager to produce alcoholic cider. Pollan likens Chapman to Dionysus, the Greek god of wine and the wild, and he believes Chapman had a better understanding than most people of the way in which humans cannot control nature.