Milkweed was influenced by Jerry Spinelli's "obsession to understand" the Holocaust growing up and personal accounts Spinelli read before publishing the novel. In an interview he says he feels one of his earliest memories are of looks at the pictures of the Holocaust. Milkweed pods are a major theme in the novel, and seems to have come from Spinelli's childhood where he used to blow milkweed pods near his home. Spinelli explains his hesitance to write a novel based on the Holocaust on feeling "unqualified" since he had no personal connections with the Holocaust other than caring about it.