A reinforced grass catcher may be positioned adjacent a cutting unit of a grass mower, the reinforced grass catcher having a pair of sides, an upper panel and a lower panel, an opening between the upper panel and lower panel facing the cutting unit, and at least one retaining structure integrally formed with the lower panel adjacent the opening. The reinforcing member may be inserted through the retaining structure or structures. Each retaining structure may be a channel, passage, opening, cavity, groove, hollow, notch, slot, hole, indentation, tunnel, port, aperture or recess that is integral with the lower panel. The reinforcing member resists or limits warping or bending of the grass catcher at or near the opening. The reinforcing member prevents loss of grass clippings through a gap between the grass catcher and cutting unit.