Abstract: The invention relates to a plastic trellis stake for supporting rows of tensioned wires 12, more particularly for supporting grape vines in vineyards, a wire support to be used in connection with this trellis stake, said stake having been provided with ribs 1a, 1b forming protuberances.A clamp 6, 7 of the wire support 5 comprises a part 6, forming seats for the protuberances of ribs 1a, 1b of the stake, and another part 7 being provided with hooks 11 for wires 12 and enclosing free ends 8 of that part 6 of the clamp.The trellis stake and the wire support are destined for supporting tendrils and twigs of plants, more particularly, grape vines in vineyards.