I hear the year falling asleep

August 21.

The air within a day or two is quite cool, almost too cool for a thin coat, yet the alternate days are by some reckoned among the warmest in the year. Young turkeys are straying in the grass which is alive with grasshoppers. The bees, wasps, etc. are on the goldenrods, improving their time before the sun of the year sets. 

The leaves of the dogsbane are turning yellow. 

There are as few or fewer birds heard than flowers seen. 

The sound of the crickets gradually prevails more and more. I hear the year falling asleep.

H. D. Thoreau, Journal, August 21, 1852

The leaves of the dogsbane are turning yellow. See September 26, 1852 ("Dogsbane leaves a clear yellow.")

The bees, wasps, etc. are on the goldenrods, improving their time before the sun of the year sets. See August 30, 1859 ("Now that flowers are rarer, almost every one of whatever species has bees or butterflies upon it. "); September 14, 1856 ("Now for the Aster Tradescanti along low roads, like the Turnpike, swarming with butterflies and bees."); September 21, 1856 ("[On top of Cliff, behind the big stump] is a great place for white goldenrod, now in its prime and swarming with honey-bees."); October 11, 1856 ("The white goldenrod is still common here, and covered with bees."); October 12, 1856 ("It is interesting to see how some of the few flowers which still linger are frequented by bees and other insects. ")