Nature plays a leading role in “The Shampoo.” Although the poem is about washing another person’s hair, the speaker spends most of their time in the realm of nature. The poem starts with a dense image of rocks and lichens on their way to “meet the rings around the moon” (Line 5). In Stanza 3, the speaker returns to nature imagery with the “shooting stars” (Line 13). The speaker washes their dear friend’s hair, and the activity brings them closer to the natural world—the moon, the stars, and the rocks. The theme of nature suggests there's something natural about what the speaker and their friend do together. Washing the hair of their “dear friend” (Line 9) isn’t an imposition or strenuous work but an effortless activity that happens on its own—similar to how the lichens “grow / by spreading, gray, concentric shocks” (Line 3) without external assistance.

At the same time, hair is natural—it’s something that organically grows on a person or animal. Looking at hair from this perspective, the nature theme and the theme of hair, or washing it, entwine. The close friend’s hair makes the speaker think of nature because their hair is a product of nature, so it has the traits of bright stars or gray shocks.