What is the primary epiphany that Taylor has in the Bean Trees?

The resolution of the relationship between Taylor and Estevan is one-sided by necessity. Taylor realizes the depth of her love for Estevan, but also realizes that she had to give him up because he is not hers. The importance of the relationship is the very fact that Taylor realizes her ability to love; she makes a final break from the idea that no man could satisfy all of her needs, and allows one to affect her deeply. It is once again Mama Greer who places this in perspective, giving her perspective and strength in this time of need, much as she did after the incident with Newt Hardbine and Jolene Shanks early in the book.

Two major themes of the novel, natural growth and female reciprocity, come together with the final anecdote concerning the wisteria vines. The information about the wisteria vines growing because of a symbiotic relationship, as Taylor explicitly states, parallels the various relationships of the novel. This highlights the fact that the growth of each character is not an independent thing: Taylor teaches Lou Ann to become more independent and assertive, Estevan teaches Taylor to open herself to love, Mattie helps Taylor take a more vast look at the world, and so forth. Lou Ann also contributes to this theme with her insistence that she and Taylor form a family: just as Mama Greer reminds Taylor, a family is not simply blood, but a bond between those who love one another. Taylor accepts this definition of family as she did not before, for it is a relationship of equality and reciprocity.

Barbara Kingsolver thus ends the novel almost as it began, with the journey of Taylor and Turtle Greer back to Tucson. Yet they return as a family engaged in a world larger than their own experiences, bound to others who similarly care and depend on one another.