A rotary plant cutter, in one example comprising: a base frame； a drum supported by the base frame； a first disk mounted within the drum and fixed to the drum； the first disk having surfaces defining a plurality of radial slots through the first disk； a second disk mounted within the drum adjacent to and above the first disk； the second disk configured to rotate relative to the first disk about a rotational axis； a drive unit having a housing fixed to the drum； and the drive unit having a shaft coupled to rotate the second disk relative to the first disk.
