The poem is recited by George Jung (Johnny Depp) in the film and is meant to reflect the feelings of the characters and the overall themes of the film, particularly the allure and danger of the drug trade.
Here are some of the lines from the poem:
> "But the leaves that fall, fall fast,
> And the roots of the tree grow deep
> Into the ground, so strong and deep
> They can't be touched by the winter's sleep."
If you are interested in the poem, you can easily find the complete text online by searching for "Blow poem" or "Irish poem Blow."