A roller cleaning assembly for a grass processing apparatus, such as a grass or turf roller, has a roller housing releasably mountable in a hollow cavity in the body of a smoothing head, where the smoothing head contains idler or smoothing rollers. A pair of roller brushes is rotatably journalled in the roller housing, and are driven by the idler or smoothing rollers via friction drive rollers. Each brush roller has at least one spiral brush and/or spiral wiper blade to clean the external surfaces of the adjacent idler or smoothing rollers and deposits the clippings or other waste in collector sections in the roller housing.