What metaphors are used in The Sky Is Everywhere by Jandy Nelson?

Lennon's grandmother is a very talented gardener who has a very beautiful garden in front of her own house. Lennon's grandmother also likes to walk through town and offer advice and to prune other people's gardens. It is thought that the roses in Lennon's grandmother's garden have aphrodisiac properties, that they make people fall in love. The garden is a metaphor for growth and love.