By the end of the book, Kincaid has accomplished a very specific goal: She has weaved together a synthetic version of what she experienced by gardening. By repeating the same basic steps for years and years, she has cultivated a whole host of associations with her flowers and design. In the end, the garden is a metaphor for her point of view, and the flower beds are like lens that she uses to view the diversity of life itself and of the human experience.
When she wants to know why the wisterias never look good on her porch terrace, she concludes that it is the stone of the terrace. The stone has a certain energy that doesn't combine aesthetically with the wisterias. In other words, she has discovered feng shui, the unseeable element of design that describes the flow of energy in a space. By listening to her instincts, she begins to find a sense of mastery in her design. What she ends up creating, therefore, is literally a picture of her soul, because she has listened to her sense of feng shui.
In case this seems far-fetched, she literally journeys to China at the end of the novel, so it isn't far-fetched at all. She pays to take her, some friends, and her publisher, all to China where they visit botanical gardens. That's where the concept of feng shui is from, and basically, feng shui is the silent argument of the whole book. Feng shui can be simply seen as another way of saying, "Every detail matters; everything is significant."
