Looking for a fall equinox-related poem, I failed. But I found this gem:
The Uses of Light by Gary Snyder
It warms my bones
say the stones
I take it into me and grow
Say the trees
Leaves above
Roots below
A vast vague white
Draws me out of the night
Says the moth in his flight —
Some things I smell
Some things I hear
And I see things move
Says the deer —
A high tower
on a wide plain.
If you climb up
One floor
You’ll see a thousand miles more.