An apparatus for cutting grass, comprising a lawn mower provided with actuating means for movement of the lawn mower at least inside one cutting area； one or more blades for cutting grass in the cutting area. The apparatus further comprises: a perimetral cable confining the cutting area and comprising at least one portion having a predetermined conformation； a management device for generating an electric signal and propagating it in the cable. The lawn mower is further provided with: sensor means for detecting the electric signal； a control unit configured for operating the actuating means in such a manner as to move the lawn mower inside the cutting area along a trajectory substantially in the form of arcs； an operating module configured for: determining main data (MD) representative of the conformation of the cable portion, as a function of the electric signal propagating in the portion； comparing the main data with reference data； generating a notification signal in case of correspondence between the main data and reference data. The control unit (60) is further configured for: receiving the notification signal； following said reception, operating in a main operating condition giving commands to the actuating means in such a manner that the lawn mower will move for meeting the cable again and will then move along the cable over a predetermined length.
