It is time to call a halt to further musings on the meaning of autumn, what with the voices of Bing Crosby and Perry Como in the air and a Christmas tree in the living room. Thus, I shall give the last word(s) on autumn to Robert Frost and Saigyo (1118-1190).
In Hardwood Groves
The same leaves over and over again!
They fall from giving shade above
To make one texture of faded brown
And fit the earth like a leather glove.
Before the leaves can mount again
To fill the trees with another shade,
They must go down past things coming up.
They must go down into the dark decayed.
They must be pierced by flowers and put
Beneath the feet of dancing flowers.
However it is in some other world
I know that this is the way in ours.
Robert Frost, A Boy's Will (1913).
Every single thing
Changes and is changing
Always in this world.
Yet with the same light
The moon goes on shining.
Saigyo (translated by Geoffrey Bownas and Anthony Thwaite), The Penguin Book of Japanese Verse (1964).