The Bean Trees begins when Taylor (whose real name is Marietta) decides that it’s time to leave Pittman, Kentucky, where she lives with her mother, and make something of herself. She buys a 1955 Volkswagen and embarks on a personal journey of self-discovery, leaving everything behind, including her name. When her car runs out of gas in Taylorville, Illinois, she decides that her new name will be Taylor. From that point on, she is known as Taylor Greer.

In the middle of Oklahoma, on land owned by the Cherokee Nation, Taylor’s car breaks down. Taylor stops to have it repaired and to get something to eat at a restaurant. Her life changes dramatically when, sitting in her car and ready to leave the restaurant and continue driving, a Cherokee woman puts a child wrapped in a blanket on the front seat of Taylor’s car. The woman asks Taylor to take the child and then disappears in a pickup truck. Taylor suspects that the child, who doesn’t speak, has been physically and sexually abused. Because the child holds onto Taylor’s clothing with a fiercely determined grip that reminds Taylor of a mud turtle that won’t let go of what it has in its mouth, Taylor names the child Turtle. Kingsolver introduces the perils of single motherhood as Taylor accepts her newfound responsibilities and makes a commitment — although Taylor is not fully aware that she has made such a commitment — to care for another human being.

Taylor and Turtle travel to Tucson, Arizona. Because of additional car problems, they end up at a business named Jesus Is Lord Used Tires. The owner of the business, Mattie, a courageous and kind person, eventually hires Taylor. Taylor soon discovers that Mattie’s shop is also a shelter for political refugees from Guatemala. After she befriends refugees Estevan and Esperanza, Taylor becomes more aware of discrimination and social injustice.

Looking for a place to live, taylor responds to an ad in a newspaper and rents a room from Lou Ann Ruiz. an immediate bond forms between Taylor and Lou Ann when they realize that they both are from Kentucky. Lou Ann, whose husband just left her, and her young son, Dwayne Ray, and Taylor and Turtle provide a sense of family for each other. The women’s friendship, the relationships that they develop with other characters, and the creation of a home in an unexpected place provide the main themes in the novel.

Eventually, the secure environment and the love that Taylor gives to Turtle pay off, and Turtle begins to speak. Her first word is “bean,” and subsequent words are the names of vegetables. One day, when Turtle is in the park with Lou Ann and Taylor’s neighbor, Edna, who is almost completely blind, someone grabs Turtle. Luckily, Edna has a cane and uses it to whack the perpetrator, setting Turtle free. Following the attack, Turtle withdraws and stops speaking. Because a social worker becomes involved in the case, it is discovered that Taylor has no legal right to Turtle and could lose her to the state if relatives are not found. Taylor, whose bond to Turtle is now no different than it would be if she were her natural mother, vows to take whatever steps are necessary to keep her daughter.

Taylor, along with Turtle, agrees to take Estevan and Esperanza to a safe house in Oklahoma. Once in Oklahoma, Taylor tries to find Turtle’s relatives so that they can legally sign Turtle over to Taylor’s care. Unfortunately, Turtle’s relatives cannot be found. Unwilling to give up, Taylor asks Estevan and Esperanza for their help. They pose as Turtle’s parents and express their wish to relinquish custody of their daughter to their friend, Taylor. Taylor adopts Turtle and then takes Estevan and Esperanza to the safe house. In the car on the way home to Tucson, Turtle names vegetables, this time including the names of the people in her family.