"Tulips" doesn't rhyme in any regular way. It also doesn't have a meter that it sticks to consistently. The fancy name for this kind of poetic form is "free verse."
However, just because this poem is written in free verse doesn't mean it isn't carefully put together. The lines don't follow a regular pattern, but the stanzas (those are like paragraphs in a poem) definitely do. There are nine stanzas in this poem, and all of them have exactly seven lines. It makes for an intriguing contrast in the poem, with such freely written lines constrained into very regular, formal stanzas.
Plus, on closer look, many of the lines themselves have their own particular rhythms. In fact, you might even say that some of the lines are vaguely iambic. Wait, vaguely what? Well, when we call a meter iambic, we mean that it follows an unstressed syllable with a stressed one, and then repeats this pattern continuously. Take this line, for example: "The nurses pass and pass" (Line 11). Don't worry so much about what the line is saying. Just listen to it.
The nurses pass and pass
ta-TUM ta-TUM ta-TUM
This meter isn't always apparent in the poem, but when it does pop up, it adds to the sense of musical flow that Plath has created with her other repeated sounds. (Take a peek at our Sound Check" section for a deeper discussion of these sounds.) It also reminds us of a heartbeat, doesn't it? It sure makes for a stirring connection when you get to that final image of her blossoming heart.
If you take anything away from our discussion of the rhythm and meter in "Tulips," remember that just because this poem is free verse doesn't mean that Plath wasn't paying attention to rhythm. In fact, she takes advantage of it at every turn. We suggest reading each line aloud to yourself, to see if you can hear any other subtle rhythms popping up.