Grape vines grow very vigorously, and most gardeners don't prune them hard enough simply because 90 percent of the growth needs to be removed each year to keep the vine manageable. Train the vine up a simple wire or wooden trellis. Grape vines must be trained and pruned while they are dormant; Oregon State University Extension Service recommends pruning from January to March. Gardeners in colder climates should wait until frost danger has passed for their area before pruning the vines.
String a wire between two poles two to three feet above the ground, leaving four to six feet in between the poles. String a second wire down from the horizontal wire to the vine, tying it to the base of the grape vine. This will serve as the trellis for the vine.
Cut off all but the strongest shoot. Let the vine grow up the wire until late fall, curling it around the wire as it grows. In late fall, prune the vine back to three to four buds if it has not gotten tall enough to reach the horizontal wire. If the vine does reach the wire, tie it to the wire and cut it off just above the tie. Allow the vine to rest for the winter and grow during the second season.
Train the vine in the second season by choosing two shoots that grow two inches under the horizontal wire. Wrap these shoots around the horizontal wire, one on each side. Cut off all other shoots that grow along the base of the vine. Grape vines that did not reach the wire during the first season will be long enough that you can train your vine this way.
Let the grapevine rest again until the following winter. At that time, prune back the arms along the wire so each has seven to eight buds. Cut off all growth from the trunk again.
Allow the vine to grow until the next winter. At this point the vine should have many long arms that grow downward from the wire toward the ground and produce fruit. Choose two canes close to the center of the plant, and cut them back so they have 15 buds apiece. Remove the other 90 percent of canes, including the old arms that wrapped around the wire. Wrap the canes you've chosen around the wire.
Repeat Step 5 annually to keep the grape vine in good condition.