What is the main setting in the novel, Wishtree?

Red is not only the novel’s main character, but also its setting. Since Red is the narrator and it is an immobile tree, all of the novel’s action takes place where Red can witness it, in the yard shared by the blue and green houses. Other characters move in and out of this setting, but the reader will only hear about other places if the characters talk about them. For example, the Mothers discuss possible futures homes, and Stephen and Samar sometimes talk about school.