The peg, made from a material with a certain elasticity, has two branches (2) with S-shaped lower ends, connected at the top (1) where they form a hole (6) for a trellis wire (5) and a grape vine (4). The peg can be fitted by pushing it down over the grape vine and trellis wire with the branches parallel or perpendicular to them, holding the two together. The peg can be made from a photodegradable or biodegradable material, and can have a number of weak points that help it to break down after a given time, or it can be designed for re-use year after year, containing anti-UV agents, colourings and other products that extend its life.