A mobile implement for mulching which provides complete control of the mulching process and uniformly distributes the mulch back upon the lawn. Grass and leaves are cut using a standard cutting blade. The mass of cut vegetation is then lifted upward into a hammermill by the trailing edge of the rotating cutting blade. The air stream generated by the rotating hammers of the hammermill forces the vegetation against a shear screen. Repeated blows by the hammers chop the vegetation to a controlled size and force it through the screen. A portion of the chopped mulch falls back upon the ground in the area of the trailing quadrant of the implement's path. The remainder of the mulch is forced into the discharge duct and blown uniformly out onto the lawn through the discharge opening of the mower housing. This same system of hardware may be incorporated into either a hand push or a power driven rotary mower as well as a gang unit, mounted on or pulled by a tractor.