Autumn joins with the maturing sun to load the vines with grapes, to ripen apples and other fruit, "swell the gourd," fill up the hazel shells, and set budding more and more flowers. Autumn may be seen sitting on a threshing floor, sound asleep in a grain field filled with poppies, carrying a load of grain across a brook, or watching the juice oozing from a cider press. The sounds of autumn are the wailing of gnats, the bleating of lambs, the singing of hedge crickets, the whistling of robins, and the twittering of swallows.
"To Autumn" is one of the last poems written by Keats. His method of developing the poem is to heap up imagery typical of autumn. His autumn is early autumn, when all the products of nature have reached a state of perfect maturity. Autumn is personified and is perceived in a state of activity. In the first stanza, autumn is a friendly conspirator working with the sun to bring fruits to a state of perfect fullness and ripeness. In the second stanza, autumn is a thresher sitting on a granary floor, a reaper asleep in a grain field, a gleaner crossing a brook, and, lastly, a cider maker. In the final stanza, autumn is seen as a musician, and the music which autumn produces is as pleasant as the music of spring — the sounds of gnats, lambs, crickets, robins and swallows.
In the first stanza, Keats concentrates on the sights of autumn, ripening grapes and apples, swelling gourds and hazel nuts, and blooming flowers. In the second stanza, the emphasis is on the characteristic activities of autumn, threshing, reaping, gleaning, and cider making. In the concluding stanza, the poet puts the emphasis on the sounds of autumn, produced by insects, animals, and birds. To his ears, this music is just as sweet as the music of spring.
The ending of the poem is artistically made to correspond with the ending of a day: "And gathering swallows twitter in the skies." In the evening, swallows gather in flocks preparatory to returning to their nests for the night.
"To Autumn" is sometimes called an ode, but Keats does not call it one. However, its structure and rhyme scheme are similar to those of his odes of the spring of 1819, and, like those odes, it is remarkable for its richness of imagery. It is a feast of sights and sounds.