Simplicity
The poem's central theme is simplicity. Form and content are aligned appropriately here, as the image of the wheelbarrow is a simple, rustic one, and the style Williams applies to his depiction of it is stripped down and straightforward. By zooming in on this image, Williams is revealing the beauty in the commonplace without falling back on ornamental language. The poem is a formal exercise in simplicity, in that it is trying to show the wheelbarrow exactly as it appears. Williams does not personify it or try to squeeze it into a metaphor, he only takes note of its utility as a tool and its delicate coating of rainwater. The poem is built upon simplicity as a means to convey its imagery. However, in showing the wheelbarrow for exactly what it is, Williams still manages to make it aesthetically pleasing.
Materiality
Fitting with the poem's ideas about simplicity, one of its other themes is materiality. In this context, materiality refers to the concreteness of the objects in the text. More specifically, this applies to the wheelbarrow, rainwater, and chickens. Williams avoids the frills of figurative language, never comparing these images to other things or imbuing them with additional qualities, whether intellectual, emotional, or otherwise. Williams depicts images with the eye of a photographer, striving for a language that shows them flatly. The poem is interested in the material circumstances of these things: the rain on the wheelbarrow, the closeness of the chickens. It never strays from their plain, exterior appearance.
Utility
Another thematic aspect of the poem is the concept of utility. The poem opens with the statement that "so much depends / upon" the red wheelbarrow. This idea can be interpreted literally, in that a wheelbarrow is designed to carry things (dirt, shovels) from place to place and as such is "depended" upon physically by the weight of these things. But utility also ties into the way that the rainwater and chickens are defined by their proximity to the wheelbarrow. The wheelbarrow is at the center of this constellation of images, providing practical service. To this end, Williams finds beauty in the image of the wheelbarrow as well as its practical application in work.
