The book follows the lives of a female apple tree and a male human who are able to communicate with each other; the tree addresses the human as "Boy" his entire life. In his childhood, the boy enjoys playing with the tree, climbing her trunk, swinging from her branches, and eating her apples. However, as time passes he starts to make requests of the tree.
After entering adolescence, the boy wants money; the tree suggests that he pick and sell her apples, which he does. After reaching adulthood, the boy wants a house; the tree suggests he cut her branches to build a house, which he does. After reaching middle age, the boy wants a boat; the tree suggests he cut her trunk to make a boat, which he does, leaving only a stump.
In the final pages, the boy (now a shriveled old man) wants only "a quiet place to sit and rest," which the stump provides. The story ends with the sentence "And the tree was happy."