Probably the most prominent stylistic feature in "The Spell of the Rose" is the symbol of the eponymous rose. In the first stanza the speaker declares that he will "Plant roses love shall feed upon." The rose in this quotation is a symbol for the love that he will offer, or demonstrate to his partner. And this love, symbolized by the rose, will be nourishment for more love to feed upon. The roses, in other words, are like a promise the speaker is offering to his partner. He promises to love her.
In the second stanza the woman replies, and says that the speaker in the first stanza "planted many trees withal, / But no rose anywhere." In the third stanza, the woman says that because he planted no roses, or, in other words, didn't live up to his promise to demonstrate his love to her, their relationship suffered. She says that "A frost-wind moved our souls to sever / Since he had planted never a rose." The "frost-wind" here symbolizes the cooling of their relationship. The implication is that all passion died away.
Another significant stylistic feature of the poem is the dialogue structure. There are two voices, but, significantly, they are not in conversation. This is evident in the second stanza when the woman refers to the man (and the speaker of the first stanza) in the third person, as "He." The fact that the two voices are not in conversation, but simply speaking about one another, suggests a distance between them. At first we might assume that this distance is because the relationship thawed and the two lovers are no longer together, but separated. At the end of the poem, however, we learn that the distance is because the woman is no longer alive, but is speaking, as it were, from beyond the grave.