From the mixture of tenses in this article you may be able to tell that I have started pruning but then fled to the internet to do more research. I will put up pictures and diagrams after I have finished pruning tomorrow...
Because of the harsh winters here, it seems as though it is better practise to prune grapes in spring, just before buds break. This is because pruning stimulates new growth, so doing this while the plant is dormant is a bad idea!
We have four rows of grapevines in a state of total chaos, supposedly growing along training wires (Guyot method). We have been trawling the internet for clues as to what to do with overgrown vines, with many, often conflicting, opinions! It’s quite maddening, but frankly I’m not going to spend too much time over it because after all I want a garden that will take care of itself. But it would be nice to have grapes and I am curious to learn about the mystical art of viticulture. So naturally what I write here are the words of a humble novice just trying to get some grapes to grow in an orderly fashion without killing the plant. The grapes at the moment have a fairly good yield although I am not sure what they are capable of so maybe it’s very poor; last year was a bad year for fruit and vegetables in the village as there was a very late frost which killed off a lot of new buds. But hopefully with a little training the grape crop will more than double with the correct pruning.
The Guyot system is one in which a vine is trained vertically up from the soil to a wire, and then trained horizontally along the wire, either just one branch in one direction or two branches trained in opposite directions (left and right). The idea is that fruiting branches grow from two main branches and are replaced each year. I am still trying to get my head round it: fruit will grow from buds only on one year old wood, so you need to replace this each year by cutting off the two year old wood and training a one year old branch along the wire in its place. And from this one year old branch grapes should grow from!
The framework we have upon which to train the vines is three rows of horizontal wires which are strung between concrete posts, so I guess it is possible to train a maximum of three stems off each grape trunk in either direction (a total of six) – one horizontally along each wire. The alternative and possibly the more correct method is to train only two branches (one to the left and one to the right) of the main trunk, on the lowest wire; these branches will sprout smaller branches as the season goes on which can be trained along and tied to the other two horizontal wires in such a way that all of the branches get enough light to make the fruit nice and sweet. Having seen how many branches and what a mass of leaves and fruit is produced in just one season’s growth it seems that this is the wiser option. So I think we will go with the latter option of just two main branches off the trunk trained along wires, as with the first method (six branches in total) there is nowhere to train the branches that are yet to grow and the vine will surely be overcrowded.
The first cautious step to take was to simply cut back the vines that were growing beyond the limits of the training wire as there was no way these would be trainable as they were just growing along the ground. Then other vines that had come loose from the wires and were growing along the ground within the borders of the wire system were reattached to the wires. Now at this stage there was still much branching and general chaos in the plants, not to mention more than one and often several trunks coming out of the root bundle, where there should only be one thick main trunk.
The plants that have more than one ‘trunk’ coming out of one root system need to be radically pruned back in such a way that only one (preferably the thickest) trunk remains. From this one trunk, one or two branches can be left and the rest pruned away. These one or two branches should be of one year old wood – certainly not older as these are useless as they don’t produce any fruit. Spotting one year old wood is simple as it has not yet hardened – two year old wood has a distinctive wizened appearance. These one or two branches should then be tied to the support wire, one to the left and the other to the right.
There are a couple of plants which have a thick mass of wood near the ground and many weedy looking ‘trunks’ that have sprouted out of it. I am in two minds as to whether to hack all of it back to ground level or to leave one trunk and prune the rest off, in the hope that it will become more substantial as the years progress. There are relics of grape plants which have been completed hacked down to the ground and subsequently died (or maybe they were killed some other way, not sure) which are a bit ominous for me, so for now I will just prune back so there is one trunk only and see how it fares because I am a wimp!
Continued pruning during the growing season is also a good idea. Pruning any branches so that they do not exceed 3 feet in length is something that I have read – the idea is that excess energy is put into fruit production as opposed to growing branches. This will also keep the vine to a manageable size. I will see how they grow and will keep them within the boundaries of the wire system, making sure that adjacent plants do not infringe on each others’ growing space.