Grape vines are easy to prune by following some simple guidelines. Wait untilall the leaves have fallen off the vine so you can see the all the stems.
Identify the main stems that provide the shape and structure of the grape vine. If these stems need to be extended then ensure the extensions are clearly identified so they are not cut off during pruning. If possible train them where you want them to go before pruning.
Once the main structure has been identified remove all the side stems back to about 25 – 50mm from the main stem. The criterion for the length is dictated by the need to have two new buds available to grow from the base of each stem.
Remove all the growth back to the main structure of the vine.