"Blackberrying" has no formal structure. It is a three-stanza poem, written in free verse. Each stanza has 9 lines of varying length, some quite long. These long lines give the poem a greater prose-like feel than some of Plath's other poems. The use of assonance and alliteration, or repetition of similar sounds, in this poem is subtler than in other poems by Plath, yet, it is unmistakably present in such passages as "Blackberries / Big as the ball of my thumb, and dumb as eyes / Ebon in the hedges. . . ."