A trellis is a garden structure that supports heavy vines and climbers by lifting them off the ground and encouraging them to grow upwards. A variety of material is used to make garden trellises, with wood being the most common. Sometimes wood on the trellis can rot, requiring immediate repair before it breaks apart. A rotted wooden trellis is unsightly and is an eyesore in the garden. This structural hazard can be dangerous for any person nearby as well as the supporting plants.
View the trellis and the framework to determine the extent of damage, and whether any of the wood is salvageable. Also access your plants to determine whether they have been damaged in any way. Use pruning scissors to cut damaged parts from the plant, and to clear them away from the trellis so you can repair the rotted parts easily.
Wear gloves and remove non-salvageable wood panels from the trellis. To do this, determine how they have been attached together. Remove any staples or wood screws with the back of a hammer and keep them aside. This will free the damaged sections that you tug and pull, and keep aside to dispose appropriately. Stubborn pieces that fail to come loose can be cut into sections with a handsaw.
Use a hammer or screwdriver and chisel to remove pieces of rotted wood from salvageable wooden boards. Do this very carefully so you do not damage the remaining length of wood. Remove the soft and wet wood until you reach the hard part, which is not damaged. Discard the rotted sections.
Sand the wood that you removed sections of rotted wood from to make it smooth. Use a putty knife to fill in sections under the hard wood with epoxy resin. It is easily available in most hardware, crafts or hobby stores and is used to repair wood, metal, glass or china, forming a very strong bond once it sets. Follow manufacturer's instructions to allow it to cure and dry.
Check to make sure the resin has dried completely. Measure the length of rotted panels and note these down on paper. Mark the measurements on a new wood board and cut over the lines carefully with a handsaw. Sand the new panels and paint them the same color as the damaged ones, if any. Attach them to the trellis with galvanized woodscrews.