Build a Grape Trellis in Four Steps
Build a trellis to support your grape plants and their climbing vines. Create supports and follow a few procedures to ensure that your structure will hold up to strong winds and under the weight of the growing plants. You must use building materials that will resist rust from weather as well as rot caused by insects and ground chemicals.
Step 1 - Trellis Posts
Your posts should be heavy and strong so as to resist wind and weight of vines. If you plan to bury them in the ground they should be treated to protect against rot, or they should buried in concrete..
Place posts about 6 feet apart and bury them 2 feet deep into the ground, assuming your soil is relatively firm. In softer or sandier soil you should either bury them deeper or set them in concrete.
Step 2 - Planning Wire Installation
Install 2 rows of wire that will eventually support vines and the grapes that grow on them—the top row about 5 feet above ground level, the bottom one 14 inches below the top wire.
Step 3 - Wire Attachment
The quickest and most secure way to attach wire to your planted posts is to drill holes in each post, 2 holes per post (as in described in Step 2). If your trellis runs east to west, drill the holes east to west. Then run your wire through the holes you've made. Leave the 2 ends of each wire loose until you have created wire anchors.
Setp 4 - Wire Anchors
You will need to keep your trellis wires from sagging, and the best way to do that is to create anchors. To do that, dig a hole in the ground beyond each end post, at least 18 inches deep and 12 inches in diameter. Fill the holes with mixed concrete. Cut two 24-inch pieces of stainless steel wire and bend each into a U-shaped loop. Bury the ends of the loop in the concrete, leaving the curved end protruding above the concrete surface. When the concrete has set, tie 1 end of the trellis wire to the secured loop. Then do the same with the other wire end, pulling it taut as you attach it to its wire loop.
Now you are ready to plant your grape root. You can enjoy the vine's fruit, secure in your knowledge that the trellis posts are firmly planted in the ground and the wire is still taut. If you have planted the vine and the trellis where the warmth and brightness of the sun reaches them, the vines will produce a nice supply of grapes for years to come.