Dig holes 2 feet deep for the support posts. Space holes for posts in the same row about 16 feet apart and space rows between 6 and 10 feet apart.
Place the support posts in the holes. Fill the holes halfway with a mixture of water and instant cement.
Support the posts with temporary strings tied to nearby standing objects or with angled temporary support stakes. Leave the temporary supports in place until the cement dries.
Fill up the rest of the holes with dirt to cover the cement.
String two or three rows of 12.5-gauge wire between the posts. Grapevines can grow at different heights, but many growers choose to place the highest trellis wire about 5 feet above the ground.
Support new grape plants by tying them to small stakes in the ground until they grow tall enough to reach the lowest trellis wire.