598386 A device for fastening movable wires on a row of plants, in particular grape vines is disclosed. A fastening device for movable wires (F', F") of a row of plants according to the invention includes connecting means suitable to arrange the device in proximity of a head pole (PE) of the row, guide means (2) and a plurality of mounting means for a wire slidingly connected to the guide means. The device is characterized in that the guide means include a plurality of guide portions (4A, 4B, 4C, 4D) that define a corresponding plurality of displacement paths of the movable wires distributed on opposite sides of the row, the displacement paths being oriented transversally relative to the direction of extension of the movable wires (F', F"). The mounting means are designed to receive a single movable wire so that each one of the movable wires is independently displaceable along one of the displacement paths.