A lawnmower (10) that comprises:a support frame (20)；a device (40) for cutting grass；a collecting container (50) connected to the cutting device (40) by means of a conveying conduit (45) connected to an inlet (52) of the collecting container and provided with an outlet opening (53) for unloading the grass from the collecting container (50)；a cover (60) movably connected to the collecting container (50) selectively between an open position and a closed position of the outlet opening (53)； anda bulkhead (54) delimiting an edge (531) of the outlet opening (53) and movable, when the cover (60) opens the outlet opening, between a first position in which the outlet opening (53) has a minimum size, and a second position in which the outlet opening (53) has a larger size than the minimum size.
