The Greenthumb Gardener's Handbook, produced by the New York City Department of Parks and Recreation, serves as a comprehensive guide for managing community gardens in NYC. It outlines essential terms, garden regulations, and best practices for creating and maintaining vibrant community spaces, emphasizing the role of volunteer gardeners in revitalizing urban areas. The handbook also highlights the importance of adherence to guidelines and preparation for successful garden management to ensure long-term sustainability and community engagement.