Winter is heralded by the vines dropping their leaves, which by then have turned from green to yellow or brown. Colder night-time temperatures signal the vines that it’s time and the flow of sap slows. After the first bout of cold weather, usually in early-mid June (in Southern Hemisphere), we feel comfortable about starting to prune. The vine is dormant, the sap is not flowing as actively, and we know we won’t be damaging the vine by pruning, only removing the wood we don’t need or want. Pruning is a process that controls the size of the vine and the distribution of buds from which growth will occur in spring.
Pruning is the most labor-intensive period of our vineyard year, not counting harvest, of course. Pruning is just as important for wine quality as a careful harvest because it allows us to control the amount of fruit a vine will bear next year. This in turn affects the intensity of flavor, and the fruit’s location on the vine, which affects its exposure to sun, light and air and therefore how well it will ripen. Electronic pruners have helped make the pruning process quicker but there is still the task of ‘pulling out’ or removing the cut off shoots.
A strategy is developed for the vineyard and this dictates how the pruning will be approached. The main decision making process involves deciding on type of pruning and the number of buds to be left on the pruned vine. In deciding how many fruit-bearing buds to leave, we treat each vine as an individual, balancing the crop load to the vine’s age, size and vigour. For every bud left on a spur or cane (previous year’s growth) during pruning, there will likely be 1-2 fruitful shoots with 2-3 clusters of grapes per shoot. If shoots push out from other parts of the vine, they will be removed during bud rubbing, de-suckering and later shoot thinning.