Grape plants are vines that need support in order to grow into a thriving crop, even for the home garden. Fortunately, you can build a simple trellis with posts and galvanized wire which is suitable for all grape vine varieties. Grapes need lots of sun, therefore, trellises should be built in a east-west direction in order to give the plants as much sunlight as possible.
Select sturdy wood for your trellis posts. It should be treated to prevent it from rotting. A popular treatment for grape vine is wood that is pressure-treated with chromated copper arsenate (CCA) or home-treated with copper aphthenate (allow 1 week of weathering before planting grapes). Do not use wood that is treated with oil-impregnated pentachlorophenol or creosote, which can harm the grape vine.
Secure your posts about 2 feet into the soil and about 5 feet above the ground. Place posts 15 feet apart.
Use large staples to staple into the middle posts. You will thread the wires through these staples in the next step. Place the staples on the windward side, meaning the side from where the wind is coming. Staple 36 to 46 inches above the ground and then another one at near the top. Do this for all the poles at the same location.
Thread no. 9 or 10 gauge galvanized wire through the staples (at the same height) on each post. On the end posts, use turnbuckles, available at most home and garden stores, so you can loosen and tighten the wires as the weather warms and cools.
Add a stake at the planting site of each plant, only for the first year. In that first year, as the vine grows, pinch off all other off shoots and only let one grow. This will be the trunk. When it's long enough, loosely tie it to the stake and then on the first wire of the trellis.
Allow two branches grow just below the first tie. Tie one to the left and the other to the right on the first wire. Allow another branch to grow upwards toward the second wire. Tie and again, allow two branches to grow below the second wire and tie one to the left and one to the right. Pinch off all other branches.