Free verse poetry does not have a set meter or rhyme scheme. It has no specific structure. Free verse poetry can have as many stanzas as the poet chooses so this is not a deciding trait. Free verse poetry can also use figurative language such as alliteration, onomatopoeia, hyperbole, metaphor, simile, symbolism, etc. These do not make it free verse. The same goes for repetition. Repeating words does not make a free verse poem free verse or not free verse.
"So Eden sank to grief", The "so" at the beginning of the line means "just as," which means that in line, the speaker is comparing mankind's fall from the Garden of Eden to the change from gold to green he described in the first half of the poem.
