Device and method for collecting leaf and yard debris, including an apparatus comprising a flexible thermoplastic sheet having a top portion and a bottom portion that are connected or partially connected. Embodiments include a two-piece design with separate top and bottom portions that are reversibly, semi-permanently, or permanently connected, so the two portions can be folded for storage. Other embodiments include a one-piece design having left side and right side cut-out areas and horizontal slits. In each embodiment, the top portion can be rolled into a cylindrical shape independently of the bottom portion, which maintains its planar configuration. Once rolled, the cylindrical top portion can be inserted into the opening of a lawn bag, and the material tension expands the cylinder to snugly fit the bag opening, thereby aiding in collecting leaf and yard debris.