There is a long history of wine making from large vineyards and backyard gardens going back several thousand years. Like most perennial plants, vines need dedicated maintenance if they are to survive for years of productivity. Pruning grapes is one of the three main tasks of the grower along with weeding and pest control. Pruning is the way to encourage the vine to grow and produce a bountiful crop of good wine-making grapes.
During the first year the main uprights are grown with all other shoots being cut back. Vines grow from one main trunk from the roots though some growers allow a second upright to grow during the second year and cut back the weaker one during the next dormant period. The young upright is tied vertically to the trellis. During the second year two main arms are trained from the trunk to the trellis. It’s from these arms that the annual crop of grapes comes from and all other shoots are again cut back.
Once the basic shape of the vine is established pruning continues through the dormant period, usually around February or March so that the worst of winter is over but before the next growing season. For large vineyards where pruning is a long process the grower will need to plan ahead so that pruning is finished by the end of March.
About eighty to ninety percent of new wood is pruned each year from the vine because fruit only grows on shoots from one year old canes. Without pruning the vine would grow out of control, produce more new wood with lots of fruit but there would be too much fruit for the vine to support and it wouldn’t ripen. European grapes tend to produce more foliage than the hybrid types and this can result in too much shade for the grapes to ripen so this also must be controlled.
The size of the crop is controlled by removing the fruitful buds. If the vine is not pruned enough it will bear more fruit than it can successfully ripen and reduce the crop for the following year by not having enough fruit bearing canes. Pruning too much will result in producing too much wood and not enough fruit and prevent the vine from properly maturing. Pruning grapes is therefore a critical part of controlling the quality of the crop.
Hand held pruning shears are all that is needed for pruning one year old canes but a handsaw or a lopper can be used for established wood. With a saw it will be necessary to avoid injuring the vine accidentally and a lopper might be better for a quick and safe cutting. It is also easier to use a lopper for places that are hard to get at.
A little experience is worth more than a lot of reading, so don’t be afraid to get stuck in. You might try taking some before and after photos of your first attempts and make notes about the following year’s crop. The art of pruning grapes is not difficult to acquire and most growers pick it up quite easily.