"Officials are encouraging the practice for its cost savings: Westchester spends $3.5 million a year on private contractors who haul away leaves in tractor-trailers and bring them to commercial composting sites in places like Orange County, N.Y., and Connecticut. At the same time, environmental groups and horticulturalists are praising the practice's sustainability, devising slogans like "Leave Leaves Alone" and "Love 'Em and Leave 'Em."" Lisa W. Foderaro in The New York Times