Mel Jones asked a very good question about pruning, and I decided to post the answer in the blog. I consulted with Daniel LLose before replying, so that is the explanation for the unusually detailed technical information in this posting!
“How do you time and organise the pruning? Do you start at one side of a site in December and just work across to the other, then on to the next site or go variety by variety, old then new vines, or some other system. Also, is there any plot/variety that you prune later, to postpone budburst, or to make anything else happen or not. I suppose I’m asking for Pichon, but would be interested to hear about Suduiraut as well.”
The purpose of pruning a vine every year is multiple: to regulate the vine vigour, to control the vegetative state and to ensure a perfect sanitary state.
The basic principle of pruning rests on the fact that the fructiferous buds (ie the shoot that will grow from this eye will bear fruits) are positioned on wood from the preceding year. Pruning has therefore the aim of remodeling a vine plant in order to keep a certain length of wood (in one or two canes) on which there will be a clearly defined number of buds (according to the criteria laid down for production volumes). Each bud will give a new branch which will bear one or two fruits according to the grape variety.
The pruning of the vine can only take place once the sap is descending, so that the plant is going into hibernation. In general, we consider that it is possible to prune when the leaves have fallen. It is also easy and more convenient to prune without leaves. The pruning begins here in mid-November and can last throughout the winter. One can prune until the end of March. But at this time, the plant is beginning its activity again, the sap is therefore in rising mode, and they say in the vineyard that “the vine is crying” since the sap can drip from the wood cut during pruning. Some properties organise pruning by teams in order to advance more quickly block by block.
At Pichon for example we practice pruning by “prix-faits”. Each vigneron has the same parcels to prune each year: it is the group of these parcels that is known as a “prix-fait”. The notion of “prix-fait” implies therefore a separation of the vineyard into individual parcels, both in terms of prix-faits and in terms of vignerons. The fact that each vigneron takes care of the same parcels every year is a big qualitative advantage. Each individual vine is thus always pruned by the same person who can from one year to the next direct the development of the vine and better preserve its longevity if he respects the rules of good pruning.
The concept of “prix-fait” indicates also a method of remuneration: the vignerons are paid by the “prix-fait”, that is to say x euros per thousand vines pruned. The prix-fait of a vigneron is carefully made up of a blend of different parcels so that each vigneron has a judicious and balanced mixture between the different grape varieties (at Pichon Cabernet Sauvignon, Merlot and Cabernet Franc) and the differing vigours of the parcels, this vigour being chiefly in relation to the age of the parcel: the older the parcel becomes, the lower will its vigour be.
The pruning method used at Château Pichon-Longueville Baron is the Guyot Double.
A vigneron can prune between 800 and 1000 vines per day. During a pruning campaign, the vignerons of Pichon have on average 50,000 vines to prune. But the work of pruning itself is not the only work that the vigneron has to do during this period. It is also necessary to prepare the vine so that it is ready for the next vegetative cycle. Pruning in Guyot Double is a method that makes trellising obligatory.
When a vigneron has finished pruning a parcel he must restore to good condition the structure that supports the vine, that is to say the posts and the supporting wires. This work is undertaken before the “pliage” which means tying down the canes. The ‘pliage’ consists of attaching the two canes of a vine plant, to the supporting wire, so that the shoots that sprout from the buds of this cane grow according to the plan of the vegetation). This dimension of the “prix-fait” enables the vigneron to prune all his parcels within the time available.
The pruning work is organized in a methodical way. The pruning plan parcel by parcel is made according to the grape varieties but also according to the precociousness of the terroirs. In general the more precocious terroirs are pruned last so that the vine does not start its vegetative cycle too early: this can limit the effects of frost at the beginning of Spring. In fact a late pruning will retard the budburst of the vine (the phase during which the buds begin to open). The young vines (of less than 5/6 years) will always be pruned last as they always tend to start their vegetative cycle earlier than older vines. By pruning them last, one also retards the beginning of the vegetative cycle.
It is not the case at Pichon since the terroirs are such that they represent very few risks of Spring frosts, but there is also a way of diminishing that risk by pruning in two phases. Pruning in guyot double is a “long” pruning method: the canes of wood (called in the Médoc “astes”) have a length of about 50 cm on which will remain at the pruning only 4 or 5 buds. The cane is kept longer in order to enable it to be attached to the supporting wire (the “attachage”). The useless buds at the end of the wood are therefore removed: the cane of wood is debudded on a third of its length.
To avoid risks of frost in very cold terroirs, the cane is maintained straight without being attached. In this position, the terminal buds will open more quickly and thus delay the opening of the buds at the base of the cane. If there is a spring frost, in this way only the terminal buds will be affected since the buds which are important for the production of grapes will not be sufficiently open. It is then only necessary to prune the vine a second time to remove the terminal buds and to attach the cane to the supporting wire.
In relation to the pruning at Château Suduiraut for example the principles are exactly the same, the important difference being that the pruning method is totally different. The pruning at Pichon is “long” with two canes of wood with 4 or 5 short spurs with two eyes enabling the reshaping of the plant in the following year.
The pruning at Suduiraut in particular and in Sauternes in general is a “short” pruning. It is not far off being a pruning ‘en gobelet’ ie for single bush vines, but the gobelet is positioned in a single line which is that of the row of vines in order to permit an efficient trellising of the vegetation.
Each short spur is composed of two eyes and the 4 or 5 arms of the vine making up the vine have been formed in order to make a fan, positioned in the row of the vine.
One can call this method of pruning a “planned gobelet”. Given the grape varieties in question (Majority Semillon and a little Sauvignon Blanc) this short pruning makes it possible to reduce the potential yield of each vine. This low yield is obligatory in order to have the earliest maturity possible. This element of early maturing is essential in order to enable the botrytis to install itself on the ripest grapes possible.