Symbolism, Imagery, Allegory
Almost every plant that appears throughout The Bean Trees could be said to by symbolic, allegorical, or metaphorical. That's a lot of lit devices! Yup, Barbara Kingsolver certainly isn't one to let an opportunity for deeper meaning slip by when she sees it. Whether you take the night-blooming cereus on Edna Poppy and Virgie Mae's porch as a "sign," as Lou Ann does (13.150), or the dozens of cactus plants that appear throughout the novel as symbols of life in times of hardship and drought, there's always something to consider when new plant species are highlighted in the book.
Wisteria Vines / "Bean Trees"
The single most important example of this trend is the one that gives The Bean Trees its title. Believe it or not, the novel's titular "bean trees" aren't actually bean plants at all: they're wisteria vines, which are a lot more purple and flowery than most beans you can think of. Let's take a look at how this confusion comes about.
Taylor first notices the wisteria vines when she and Lou Ann start taking Turtle and Dwayne Ray to Roosevelt Park, where they often sit under a wooden trellis that has vines growing all over it. Taylor tells us: "All winter Lou Ann had been telling me they were wisteria vines. They looked dead to me, like everything else in the park, but she always said, 'Just you wait'" (8.49).
When the wisteria flowers do eventually bloom, it seems like something of a miracle to Taylor, who could hardly imagine anything beautiful coming out of something that looked so dead:
"Toward the end of March they had sprouted a fine, shivery coat of pale leaves and now they were getting ready to bloom. Here and there a purplish lip of petal stuck out like a pout from a fat green bud. Every so often a bee would hang humming in the air for a few seconds, checking on how the flowers were coming along. You couldn't imagine where all this life was coming from. It reminded me of that Bible story where somebody or other struck a rock and the water poured out. Only this was better, flowers out of bare dirt." (8.50)
Even at this point, the wisteria vines have symbolic significance. To Taylor, they represent the miraculous potential for life to emerge from death (or what looks like death, anyway). Although Taylor doesn't yet make the connection explicitly, it's clear that the wisteria vines share something in common with Turtle, who has been given a new opportunity to grow and thrive despite the abusive home life she suffered before she was given to Taylor.
This connection becomes even clearer later in the chapter when Taylor takes Turtle to Dr. Pelinowsky's office. When Dr. Pelinowsky realizes that Turtle is actually much older than she appears, he tells Taylor: "Sometimes in an environment of physical or emotional deprivation a child will simply stop growing, although certain internal maturation does continue. It's a condition we call failure to thrive" (8.146).
When Taylor suggests that Turtle seems to be "thriving now," Dr. Pelinowsky replies: "Well, yes, of course. The condition is completely reversible" (8.147-48). Remind you of any planty parallels?
In Chapter Ten, which is called "The Bean Trees" (hey! Just like the title!) the symbolic significance of the wisteria vines becomes even more explicit. One afternoon, while Taylor and Lou Ann have Turtle and Dwayne Ray at the park, Turtle decides that the wisteria vines look an awful lot like bean trees:
"Turtle shook her head. 'Bean trees,' she said, as plainly as if she had been thinking about it all day. We looked where she was pointing. Some of the wisteria flowers had gone to seed, and all these wonderful long green pods hung down from the branches. They looked as much like beans as anything you'd ever care to eat.'
"'Will you look at that,' I said. It was another miracle. The flower trees were turning into bean trees." (10.19-20)
Not only does this passage make it 100% clear that the so-called "bean trees" of the novel's title are actually the wisteria vines and the pods they're sprouting, it also deepens the connection between the "bean trees" and Turtle. After all, "bean" was Turtle's very first word (7.49). Look at all those symbols intertwining!
The final significance of the "bean trees" becomes clear in the novel's final chapter, which is called " Rhizobia," which we'll define in a minute. While reading about wisteria in the Horticultural Encyclopedia, Taylor and Turtle learn that "wisteria vines, like other legumes, often thrive in poor soil" (17.137). Get ready for some more symbolism:
"Their secret is something called rhizobia. These are microscopic bugs that live underground in little knots on the roots. They suck nitrogen gas right out of the soil and turn it into fertilizer for the plant.
The rhizobia are not actually part of the plant, they are separate creatures, but they always live with legumes: a kind of underground railroad moving secretly up and down the roots." (7.137-38)
As Taylor's comparison between the rhizobia and the "underground railroad" makes clear, she immediately associates the microscopic bacteria with the kind of hidden networks that have helped to bring Estevan and Esperanza to safety. She also goes on to associate them with other relationships of reciprocal care:
"'It's like this," I told Turtle. "There's a whole invisible system for helping out the plant that you'd never guess was there.' I loved this idea. 'It's just the same as with people. The way Edna has Virgie, and Virgie has Edna, and Sandi has Kid Central Station, and everybody has Mattie. And on and on.'
The wisteria vines on their own would just barely get by, is how I explained it to Turtle, but put them together with rhizobia and they make miracles." (7.139-40)
If you need more convincing that this is a forceful symbol for the power of family, friends, and community, we can't help you.