Grape vines need to be trained to grow upward on a trellis for maximum sun and air exposure. Training your grape vines to grow on a three wire trellis will provide that for the grape vines and make harvesting the grapes easier for you.
The main building materials for building a grape vine trellis are wooden posts and wire. You will also need post hole diggers, fence staples and perhaps a come-along to tighten the wire.
Choose wooden post to build a grape vine trellis that have been treated or seasoned, since the wooden posts will be sunk into the ground and exposed to the elements for years to come. Pressure treated 4 x 4’s, seasoned cedar or seasoned locust posts make excellent choices. The wooden posts should be two to four inches in diameter and eight feet long.
How many wooden posts you will need to build a grape vine trellis is determined by how many grape vines you have. Trellis posts need to be placed at the halfway point between each grape vine, so the grape vine will be trained to grow on the wire, not on the wooden posts. You will also need two end posts for your grape vine trellis.
Dig holes two feet deep and sink your wooden posts into them. Back fill the hole with dirt, firming the dirt as you back fill. This will leave you with six feet of above ground posts to work with.
Use 10 or 12 gauge galvanized wire for a grape vine trellis. You will need enough wire to make three strands that span the length of your grape vine trellis, plus about 20 feet of wire to brace and anchor each trellis end post into the ground for trellis stability.
Place three fence staples into each of your trellis posts, one at two feet, one at four feet and one at six feet. Do not pound the staples completely into the wooden posts, these staples are used as guides for the wire on the trellis.
Secure each end post first by attaching a ground wire at the bottom of the post and a brace wire at the top of the post. Bring both of these wire together at ground level, forming a 90 degree angle and secure the wire ends on a small stake and drive securely into the ground. This will keep your grape vine trellis from bowing in as the trellis become heavy with ripening grapes.
After the end posts are secure, fasten one end of the wire to the end post at the bottom staple and run it through all the other bottom post staples, pull the wire taunt, cut and fasten the wire at the opposite end post. Repeat the process through the middle and top post staples.
Train your grape vines to grow on the wire, loosely tying the grape vine shoots as they grow upward on the grape vine trellis.
