An apparatus for spraying a treatment liquid onto grass growing on a ground surface includes a plurality of rotatable discs spaced laterally apart across the path of travel. Each disc has a plurality of cutters which are adapted to penetrate the ground surface and to cut holes therein as the apparatus travels forwardly. The holes are spaced apart along the path of travel and are also spaced apart laterally. The apparatus also includes a set of nozzles positioned on the apparatus above the grass such that each nozzle is spaced rearwardly along the path of travel from its associated disc but is aligned along the path of travel with such disc. The nozzles are adapted to spray the treatment liquid. The apparatus also including a controller for causing the nozzles to spray the treatment liquid into the holes.