The present invention relates to a device for fastening movable wires on a row of plants, in particular grape vines. A fastening device for movable wires (F, F") of a row of plants according to the invention includes connecting means (1, 201, 301, 401 ) suitable to arrange said device in proximity of a head pole (PE) of said row, guide means (2) and a plurality of mounting means (3) of a wire slidingly connected to said guide means (2). The device is characterized in that said guide means (2) include a plurality of guide portions (4A, 4B, 4C, 4D) that define a corresponding plurality of displacement paths of said movable wires (F, F") distributed on opposite sides of the row, said displacement paths being oriented transversally relative to the direction of extension of said movable wires (F, F"), and in that said mounting means (3) are designed to receive a single movable wire (F, F") so that each one of said movable wires (F, F") is independently displaceable along one of said displacement paths.
