Abstract: A rotary mulching mower has a rotating impeller or rake mounted anteriorly of a shredder rotor assembly. The latter comprises a motor driven rotatable member or rotor supporting circumferentially spaced rows of radially extending shredding pins extending below and above the disk. The upwardly extending pins mesh with complimentary stator pins mounted on the mower housing above the shredding rotor. Leaves or other lawn debris are passed by the impeller into a manifold and then directed via a suitable baffle to the meshing pins to be shredded thereby into mulch whereas the downwardly directed pins function effectively to remove thatch from the lawn being mulch mowed.