I don't think it is necessarily about a woman.
The poem compares a pot plant with a weed growing on a mountain top.
The pot plant is beautiful, cultivated, cherished; but it is owned by someone. The flower is pampered and prized, but it is not free.
The weed (Polanco says) is exposed to the elements, and has to fight to stay alive (nobody waters or feeds it); but the weed does not belong to anybody. It is free.
It is a very silly poem; weeds grow in 'dirt' just as much as weeds do. And flowers are just as much 'exposed to the madness of the vast eternal sky' as weeds are.
(Unless you happen to believe that flowers grow beneath a small, sane and temporary sky).
The poem says the sort of thing people expect a poem to say, and says it in the way people expect a poem to say it.
Real poems never do what you expect.
but harnessed to a pot of dirt? (might be interrogative)
I'd rather be unseen, and if, (and if I'm unseen)
Ya, you're analysis I think is right. It could be about middle class lifestyle that can be boring to some people. Being respectable and constrained vs not getting respect and being carefree
Do any of you know who originally published this poem?