in Thoreau’s Journal:

The autumnal tints have not been so bright as usual this year, but why it is hard to say. The summer has been peculiarly cool, as well as wet, and it may be that the leaves have been the more inclined to decay before coming to maturity. Also, apparently, many leaves are killed by the mere frosts before ripening, the locust for instance, —and the frost came early this year, —just as melons and squashes before they have turned yellow; i.e., the leaves fall while they are still green.