Even though there are no actual people in this poem, there's one thing that we shouldn't ever forget about any piece of writing, and that's the speaker. Just by virtue of being written down on the page, "Big Poppy" brings human and nature into very close contact. If you head over to the "Speaker" section of this analysis, you can see what we have to say about who this guy might be (and develop your own thoughts on the subject, too). The relationship between human and nature in this poem is one of unabashed and intense wonder followed by a kind of grief that is no less awestruck. It also takes a human to personify as much as this poem personifies, which tells us quite a bit about how the speaker envisions man's relationship to the world around him.
The poppy's use as an opiate brings man and nature into an especially complex and dangerous relationship in this poem.
"Big Poppy" brings into relief the fact that even in our attempts to control nature, there is always wildness about us – even in our manicured gardens.