Pruning is one of the most important jobs in the vineyard as it decides whether production will be balanced the following year. Winter pruning is carried out from December to March, the months when the vine is 'asleep' and consists in shaping the plant, reducing the length of the shoots, leaving a certain number of buds in order to achieve the balance of production which the winegrower desires.
Pruning too early (before leaf fall) would deprive the plant of part of its reserves, making it more sensitive to winter cold and running the risk of making it start to wake up (budding) more slowly. Pruning too late, on the other hand (after the buds have already closed), will tend to make budding happen late. This is not always a negative feature: sometimes a delay in the plant starting to grow again may save it from spring frosts, especially where young vines are concerned.
Pruning techniques vary according to the vine-training system used, the type of vine, the vinegrower's decisions and the soil climate conditions for each individual plant.
Where the age of the vine is concerned, pruning varies according to the stage of the plant's life cycle. From planting to 2-3 years old pruning is just to create the right shape of plant. From 2-3 years to 5-6 years, a stage of increasing productivity, the plant is strongly pruned to bring it to complete maturity. In the constant production stage, from 6-7 years to 20-25 years, pruning is necessary to balance vegetation growth and production and hence the quality of the yield. In old age, up to 30-35 years, when the plant's strength and productivity are progressively decreasing pruning has to gradually become more intense.
From May onwards spring pruning is done to cut out all the sterile buds on the trunk (spur pruning) and the shoots (bud pruning and secondary bud pruning) which consume nutrients absorbed by the plant, but to no purpose.