The word "home" in The Bean Trees is of importance because it is the locus, the center, of where friendships are rooted. One of the major themes of the story is friendship. First, Missy is a strong independent character because of the supportive love and friendship (not friendship in the sense of best buddies but friendship in the sense of being ready, willing and able to give help, care, guidance and comfort) she received from her mother at home.
Second, one character after another is rescued and then redeemed by friendship and given a home: Turtle, Lou Ann, Estavan and Esperenza, and Taylor (Missy), herself. The friendships build homes for the characters, like for Lou Ann and Taylor who make a home for and with each other so they can raise their babies in peace and safety. this is also true for Estavan and Esperenza who find a sheltering home with Mattie, then later a permanent home of refuge because of Mattie and in conjunction with Taylor's desire for a permanent home with Turtle.