Pruning your grape vines is necessary in order to encourage fruit production on the plant, as well as manage the growing vines. Whether you are pruning back overgrown grapevines that you have forgotten about or found, there are a couple key things to keep in mind when pruning them back. Always prune the grape vine during the winter season.
Find the strongest and largest grape vine stem. Next, locate the two strongest stems on either side of the largest one.
Use the pruning shears (make sure they are very sharp), and cut all of the surrounding smaller stems back to the base of this larger stem, and the two second largest stems on either side of it.
Insert a wooden stake or vine stake next to the largest stem, in order to make the stem be the trunk of the grape vine. If there is already a stake there, position it so it is supporting the trunk of the vine and is sturdy.
Pinch the top of the main trunk to encourage side branching if you want more vines to branch out from the trunk. The grape vine should resemble a main trunk with two side sets of branches.
Continue to prune the side branches, but always make sure there are around 12 buds on the arms during winter, which are crucial to spring fruit production. Each of the 12 should have 1 to 2 leaf joints so the vine looks like a stubby hat rack when you are finished pruning.