Although you can purchase trellises from many retail gardens shops, making one at home is easy and saves money. A trellis is an important structure when growing grapevines because it provides them the main support for climbing upward to receive maximum sunlight and exposure. It also increases the yield by enabling a maximum number of grapevines in a little space. This essential feature used for growing grapes also helps you pick ripe fruit without disturbing or damaging the main stem.
Step 1 - Select an Open Space
It is always best to build your trellis before you plant the grapevines. Remember, each grapevine grows to become a very large plant that requires about an eight-foot by eight-foot space, so make sure you build your trellis in a wide-open area.
TIP: Our expert gardening advisor, Susan Patterson adds, "Make sure that the trellis is located in a spot where the entire grape plant will receive sunshine."
Step 2 - Make the Main Posts
Use materials, such as aluminum, pre-treated wood or PVC pipes, to make posts for the trellis. The height of your trellis generally depends on the type of grapes you wish to grow and the climatic conditions of your area. Taller trellises are used in warmer climates, while shorter ones are used for the winter.
Cut your posts to a height of three feet if you wish to build a short trellis and eight feet for a taller one. They should be three to four inches in diameter. Set them at least two feet into the ground, spacing them at intervals of about 15 to 20 feet.
TIP: Susan suggests, "If your end posts pull inwards with the weight of the grapes you can put them in concrete."
Step 3 - Make Anchor Posts
Erect a smaller stake to serve as an anchor for the wires, at an angle away from the main post. The number of anchor stakes depends on the length of your trellis. For longer trellises, you need to provide anchor stakes at each post, but for a smaller trellis of two or three posts, an anchor stake at each end is fine.
Step 4 - Attach Two Support Wires
Take the 12 gauge galvanized wire and run two lengths of it along all the posts of the trellis, with one wire about three inches above the ground and the other a foot from the top of the main posts. Make sure these two support wires are tight and stapled securely in place.
An alternative to this is to drill holes in each post, one near the bottom and another near the top, and feed the wires through these holes.
Step 5 - Attach Catch Wires
Take the lighter wire and run sections of it between the two support wires. These wires, known as catch wires, are essential for keeping the grapevines in place.
After your grapes grow, take a few branches from the grapevine and run them all along the main wire with the help of the catch wires, which will hold them in place. Your grapevines will grow upwards and along the two main wires of the trellis.