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&prime；, F&Prime；) 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&prime；, F&Prime；) distributed on opposite sides of the row, said displacement paths being oriented transversally relative to the direction of extension of said movable wires (F&prime；, F&Prime；), and in that said mounting means (3) are designed to receive a single movable wire (F&prime；, F&Prime；) so that each one of said movable wires (F&prime；, F&Prime；) is independently displaceable along one of said displacement paths.
