A few weeks ago, I traded my office desk briefly for a shaded spot between Malta’s wonderfully green rows of blossoming vines and witnessed with great respect hard-working local grape growers green prune their vineyard.
Although not always fully appreciated by lay persons, green pruning is a very important vineyard operation and an essential job in order to shape the plant in an effective and productive way.
Spanish vignerons have a perfect term for it, namely ‘espergura y desniete’, which translates rather regimentally to ‘clean up and deny’.
In fact, the task is to selectively remove unwanted foliage from the main trunk and deny the vine to grow too many new leafy green shoots which could drain the plant’s resources and form more flowers and grape clusters than desired for the production of quality wine.
Green pruning is basically the act of lessening the vegetative growth to trick the vine, a vigorous sprawling climber by nature, into devoting its energy to the maturation of better grapes with more concentrated flavours for winemaking.
The use of proper pruning techniques allows for appropriate sun exposure and improves the flow of air within the plant and in between grape bunches to prevent diseases (such as powdery and downy mildew) so that healthy berries ripen fully and evenly.
If left to develop at will, the excess of vegetative growth would let valuable energy and nutrients go to waste. They are better directed towards the ripening and maturation of the grapes in summer but also to the general development of the vine plant and, at the end of the vineyard year, to accumulate reserves for the following vintage.
The task of breaking off unwanted shoots may seem straightforward but it requires skill. When done properly, the vine itself suffers from fewer pruning wounds and infections and gets to live longer. On the whole, green pruning increases the efficiency of the vineyard and the return on investment for the grape farmer.
I estimate it takes about 45 seconds on average to green prune one single vine plant. Given a planting density of 5000 to 5500 vines per hectare, it must still take around 55 man-hours to complete a vineyard the size of a football field. This might be time-consuming, but green pruning is unquestionably vital to growing world-class grapes for top-flight wines.
This article by Georges Meekers appeared first in the Times of Malta, 16 June 2017.