in Thoreau’s Journal:

I climb Anursnack—under this strong wind—more dry oak leaves are rattling down—all winter is their fall— A distinction is to be made between those trees whose leaves fall as soon as the bright autumnal tints are gone and they are withered—& those whose leaves are rustling & falling all winter even into spring. October is the month of painted leaves—of ripe leaves—when all the earth—not merely flowers—but fruits & leaves are ripe— With respect to its colors & its season it is the sunset month of the year—when the earth is painted like the sunset sky— This rich glow flashes round the world— This light fades into the clear white leafless twilight of November—and whatever more glowing sunset—or Indian summer we have then is the after-glow of the year— In October the man is ripe even to his stalk & leaves—he is pervaded by his genius—When all the forest is a universal harvest —Whether he possess the enduring color of the pines which it takes 2 years to ripen & wither—or the brilliant color of the deciduous trees which fade the first fall.