What is the theme in The Force That Through the Green Fuse Drives the Flower by Dylan Thomas?

The Force That through the Green Fuse Drives the Flower" describes the cycle of birth and death. It is one of several poems by Thomas which explores this pattern; in fact, the pattern provides such a consistent theme throughout his work that some critics have categorized this group as process poems. As the poem opens, the speaker presents the creative and destructive forces in life and nature.