in Thoreau’s Journal:

While the grass is fresh the earth is in its vigor. The greenness of the grass is the best symptom or evidence of the earth’s youth or health.

Perhaps it will be found that when the grass ceases to be fresh & green or after June—the birds have ceased to sing—& the fireflies too no longer in myriads sparkle in the meadows—

Perhaps a history of the year would be a history of the grass, or of a leaf, regarding the grass-blades as leaves, for it is equally true that the leaves soon lose their freshness and soundness, and become the prey of insects and of drought…