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.