Ultimately, this poem is about understanding love and becoming symbiotic with nature, as symbolized by the "country senses" which augment the five ordinary ones with which each person is imbued. Through one's "country senses," or rather, when the "country senses" become able to fully perceive, we "forget green thumbs"—that is, forget the idea of interpreting nature and the world pragmatically, as something which results from our tending and our hard work. Rather, we will begin to perceive how the "vegetable eye" of the halfmoon pares, or carves out, love "in the frost" and then sets it aside for winter, the suggestion being that even the cold parts of nature, such as the winter frost, are an articulation of love.
The "whispering ears," Thomas writes—suggesting ears of corn, as well as something that both listens and speaks—will "watch love drummed away." There is a certain synesthesia in this description: the "ears," which should be organs for listening, are portrayed as both "whispering" and "watching." Thomas repeats this concept as he speaks of how "the eyed tongue talk[s]" while his "nostrils see her breath burn like a bush." The appreciation of love is such that it seems to confuse and jumble the senses, according the "wrong" sense to each organ as the "discordant" intensity of nature becomes too much to process.
These jumbled senses are contrasted to the speaker's "one and noble heart," which, he says, "has witnesses in all love's countries, that will watch awake." Here, in the final stanza, the sense of synesthetic confusion falls away, and the words—"watch," "awake," "blind sleep," "spying"—all form part of the same semantic field of eyes, vision, and watching. The "noble heart," then, perceives without confusion, and in our sleep, when the "spying senses" are dulled, "the heart is sensual, though five eyes break." The conclusion seems to indicate that the heart alone is able to truly understand what the senses perceive, as the senses themselves are unable to accurately interpret love. Love is not something that can be broken down piecemeal into elements we can see, hear, taste, or articulate. It can be understood only by the heart, or "country sense," which does not think, but only feels and becomes a filter for what love really is.