Growing grapes in your backyard can create a bountiful supply of fruit for consumption or home wine making. Pruning the grape vines is an important step in the regular maintenance of the grape vine to regulate the vine's growth and ensure a good harvest. Rejuvenate an old grape vine with proper pruning to restore its productivity and enjoy the fruits of your labour.
Obtain bypass pruners with a slightly curved blade to make pruning easier and reduce strain on your hands. Examples include the Felco #8 Pruner and the Fiskars Powergear Bypass Pruner.
Prune in the late winter. Cut back all of the vines and woody growth to the grape vine's base, leaving approximately 1 foot of stump above the ground. Some old vines, especially those that are several decades old, will be too large for pruning sheers. Use a hand saw for such vines.
Erect a trellis behind the grape vine stump. Trellises may be obtained from most garden supply stores and nurseries, as well as some hardware stores. Typically, gardeners choose a trellis that is 4 to 5 feet tall to make vine management easier and the future fruit more accessible.
Allow the pruned vine to grow unchecked for one year. New growth will sprout from the pruned stump in the spring following your winter pruning. Because the vine will already have a large network of underground roots, the new stems will grow vigorously and rapidly.
Prune the grape vine again in the late winter following your previous winter pruning. Choose the tallest, strongest stem and use the pruners to cut back all the other stems to the base of the old stump. Tie the remaining stem to your trellis using garden twine or garden wire.
Let the grape vine's new stem continue to grow. This will become the main trunk of your rejuvenated grape vine. Allow new branches to sprout from the side of the main stem and train these stems along your trellis, tying as needed to keep them supported. Typically, farmers will limit the vine to four main side branches and a single trunk, continuously cutting back other growth. This allows the plant to channel all of its energy into buds and fruit on the remaining branches.
Watch for buds. Buds will form along the grape vine's side branches. For maximum harvest potential, prune back all but the largest buds along the branch to ensure large grapes.
Prune grapes in the early spring to give the vine as much growing time as possible before the next fruit season.