Drive through any vineyard during mid-winter and you will notice that the vines have been cut down to their bare bones. No leaves, no stalks, just naked cordons with stubby little shoots which have been cut back. The practice of pruning is one of the most important aspects of growing grapes.

Pruning is necessary for the vine to regenerate, as when the canes are cut off, it enables the vine to conserve energy and rest during the cold winter months. However, the main aim of pruning is to ensure a healthy yield come harvest time. Done correctly, pruning allows for a controlled quantity and quality of fruit. This is maintained by controlling the number of shoots per cordon (the straight part of the vine running parallel to the ground). Reds have two or three bunches per shoot, so by controlling the amount of shoots left on the cordon it is possible to control for the number of buds which will develop during spring. 

As with nearly everything relating to wine there is a bit of science behind the art: in order to bear fruit a vine needs a one-year shoot, growing on a two-year shoot, growing on a shoot which is more than two years old. This ensures that the canes which develop are mature enough to yield grapes which are ready to be made into wine. It also means that the person doing the pruning can’t just cut and chop as they please; they need to know what they’re doing. Some vines have larger shoots called casanaves. These thicker shoots have more buds (about 6 – 8 ) and hence more fruit zones. However, more does not always mean better. The theory of apical dominance means that the further away from each other buds are, the better the resultant bunch will be (every bunch enjoys some space to grow and develop).

Fruit needs about 45 – 60 days hang time from veraison (when the fruit changes colour) in order to ripen fully. As a result of our cool climate at Steenberg, our grapes ripen very slowly thus the idea is to prune earlier than most other vineyards. The earlier you prune, the earlier the vine will bud and thus the earlier it will ripen.

So what would happen if you didn’t prune at all? The vine will produce more fruit than it knows what to do with because when you prune a vine correctly, you remove as much as 95 to 98% of the previous season’s growth.  If you leave all of that growth from the previous year it will develop buds, increasing the crop for following year. It will be an uncontrolled mess!

The vine cannot produce enough energy to ripen an unregulated crop, and thus the crop will be poor quality. The clusters will be dishevelled, and you won’t have much fruit worth using.  Even if it is able to ripen, the vine will have diverted energy that it might ordinarily use to mature the wood and to help the vine get ready for winter.

So in essence, when we cut away at the vine we are giving it the best chance to grow: a form of botanical reverse psychology!