In a piece of literature, a motif is closely related to the theme of the work. A motif is an image, event or action which helps to support the theme. In Gary Soto's novel Buried Onions, the most powerful recurring motif is the onion. The onion is a symbol for the tears which are shed by those who are part of the poverty ridden Mexican-American neighborhood in Fresno where Eddie grows up. In the first chapter, Eddie recounts the sorrows of those from this barrio, including his best friend Juan, who died in a work accident, his sister Belinda, whose husband Junior is in prison, and his cousin Jesús, who is stabbed to death in the bathroom of a nightclub. Eddie suggests that in the heat of summer there are "vapors" which emanate from the ground and are caused by a giant buried onion (if you've ever peeled or chopped an onion you know that they can cause involuntary tears), which is responsible for all of the problems he and those trapped in his neighborhood have to endure. He even notes that Belinda has a permanent tattoo of a tear on her cheek.
While metaphorically prevalent throughout Eddie's narration, real onions also surface during the story. In Chapter Four, Eddie's friend from high school, José, comes home from the Marines. José has seemingly escaped the poverty and violence of the barrio and is about to be shipped out. To celebrate, he takes Eddie out to breakfast, but afterward they are accosted by a man selling onions. José, simply attempting to demonstrate his generosity, agrees to buy some onions from the man. On the way back from buying the onions, Eddie sees Mr. Stiles's truck, which had recently been stolen from him. When José attempts to help him, he is badly stabbed. The incident seems to reinforce the inability of anyone to escape the despair of the barrio. The fact that onions are involved tends to strengthen Soto's recurring motif.
In Chapter Six, when Eddie believes he has received a reprieve from Mr. Stiles, he returns to the man's house to help plant trees. While digging, he discovers an onion-like bulb. Immediately after this discovery, he is arrested for the theft of Mr. Stiles's truck. Again, the onion shows up in times of trouble. Finally, in the last chapter, Eddie finds himself in a field of onions. He falls to the ground in tears over his childhood scars and the death which has pervaded it. Symbolically, a fieldworker hands two onions to Eddie seemingly as a way to absolve him of all that he has experienced. He comments that his eyes "filled and closed on the last of childhood tears."
Death and the prevalence of the cholos and gangbangers which infest the barrio also find their equivalents in literary motifs in Soto's work. The strongest motif of death is Eddie's obsession with the mortuary students at the city college. He imagines that their hands are cold and that the dead bodies steal heat from them so that when they return outside they need to stand in the sun to replenish their warmth. Another motif for death occurs in Chapter Five, when Eddie takes his nina's (godmother) dog to the humane society to be euthanized. Poverty is also symbolized when Eddie pockets the money that was meant as a donation to the SPCA. A motif which suggests the prevalence of the gangsters which plague Eddie is symbolized by the cockroaches that live in his apartment. No matter what lengths he takes to exterminate them, they always seem to come back, similar to the recurrence of cholos like Samuel and Angel throughout the novel.