Critics interpret "The Force That through the Green Fuse Drives the Flower" in a number of different ways. For M. L. Rosenthal, it is basically a tragic poem. In The Modern Poets: A Critical Introduction, he analyzes Thomas's style, asserting that the power of his poetry, particularly in his early work such as this poem, lies not in his themes but in the grandeur and power of his language. Like many critics, he finds the poem's ideas about the cycle of birth, growth, and death in man and nature the least compelling aspect of the poem. Rosenthal traces the comparison between man and nature and man and sub-organic nature through the first three stanzas. The fourth stanza reveals the tragic premise he finds in the poem. Although it reveals a passionate desire for a union, or communion, between all living things and the force which governs them, this is not possible. "The poem ends in despair, with a bizarre and deliberately ugly phallic image that, in degrading the symbolism of the fourth stanza, doubly underlines the anguish out of which it has arisen."
In Entrances to Dylan Thomas's Poetry, Ralph Maud sees "The Force That through the Green Fuse Drives the Flower" as an expression of the unity of life. He classifies it as one of Thomas's process poems, using the balance of symbols such as the crooked rose and the crooked worm to support the poem's antithetical organization. The shift in positive and destructive imagery in stanza three, instead of being "subversive," develops the point that the life and death forces are the same. For Maud, the poem shows that positives flow from negatives. The lime pit where the dead are placed has a cleansing function. Leech is an archaic term for a doctor, and a loss of blood may be beneficial. For him, the central focus is "the idea of the unity of contrary forces."