A walker in cold boots passes through the tidy, cultivated parts of the landscape: a field, a vineyard, a garden. In each of them he looks for something living and wild, and the poem's blunt line "no flowers" tells us he finds nothing. These are places shaped by people, and they seem bare or empty to him, perhaps because of the cold season the boots suggest.
So he turns around. The last lines send him back to the fen, the wet, untamed ground where, as he puts it, he "found / all things." That phrase is large and a little startling after the sparse lines before it. It suggests that a marsh, messy and unplanned, holds more variety and life than any ordered plot.
The mood is quiet, plain and slightly wry. The speaker doesn't complain; he simply decides where to go. The short lines move like steady footsteps, and the poem ends with a sense of return and quiet loyalty to wild places.