There is a place where the sidewalk endsAnd before the street begins (1-2)
Before we've even heard about grass or trees, the poem has placed us in a world that we know is far away from the city and the suburbs, because there are no sidewalks or streets there. These lines ask us, what if the world was not marked out in grids of roads and traffic lights? What if there was something out where the streets couldn't reach?
And there the grass grows soft and white, And there the sun burns crimson bright (3-4)
If we weren't reading carefully, we would think that these lines give us a description of any old nature scene. But, luckily, we've got our thinking hats on, and can detect that there's something up in these lines. These descriptions seem a little… off. So where exactly is this world where the sidewalk ends?
And there the moon-bird rests from his flightTo cool in the peppermint wind (5-6)
Have you heard of a peppermint wind? Or a moon-bird for that matter? Along with the slightly off details of the lines prior to these two, we're starting to realize that nature, in this poem, is not just nature. It's a world where the imagination is most free to run wild.