The North – Winter at Pietershof
Never a dull moment as a winemaker. You might think that after harvesting and fermenting, the wine needs rest to settle in the cellar and perhaps further develop. The cue for any vintner to finally enjoy some well-deserved rest, like the beach café owner that takes off to the far-away sun in winter?
Alas, the winter months must be used to do some essential pruning when the vines are dormant. The vine is basically a liane and produces an incredible amount of unproductive wood if left alone. Even with proper pruning throughout the year, you’re still left with a myriad of canes that need to be trimmed down drastically.
Through winter pruning a vintner can remove as much as 90% of a year’s shoot growth. That’s a lot of wood. To give you an idea, here’s a picture before and after pruning.
Pruning typically starts after all leaves are gone. When the leaves are still on the branches, the vine is still busy getting nutritional stuff into the trunk before going into hibernation. Pruning during this time could affect next year’s crop.
If a vintner wouldn’t prune, s/he would end up with numerous bunches of grapes. Impossible to get them all fully ripen, especially at Pietershof where it doesn’t get much cooler in terms of winegrowing. It would also exhaust the vine too much resulting in a shorter lifespan.
So by winter pruning, many buds (the small knobs on the stem that develop into a shoot) that would otherwise become new shoots are removed. This way, the growth is concentrated in the remaining shoots that will produce leaves and grapes.
Through pruning, a vintner can also maintain the form of vines. Usually, some guiding system of wires will be used, a so-called trellis system. While growing, vines will use tendrils in the shoots to attach themselves to these wires. Keeping vines in a similar shape makes it easier to work the rows with vines, e.g. for spraying with a tractor or harvest.
Therefore, pruning is essential but it is a lot of work, and is one of the most costly operations in the vineyard. It could be done mechanically, but as every vine is unique it takes a trained eye to make the necessary cuts at the right place.
Until technology is able to take over the vintner’s expertise, pruning will remain a tedious manual labour. Depending on the vineyard’s size, it can take from November to April, when budbreak starts.
Traditionally, there are 2 main ways of pruning, either spur or cane. At Pietershof, they started pruning in a different way. This has mainly to do with a vine disease called Esca. This is a so-called Grapevine Trunk Disease (GTD) and appears to manifest itself increasingly in vineyards all over the world, apparently even more in cooler climates.
Could Esca be the next big thing in vineyard destruction?
There is still little known about Esca, but together with other GTDs its impact could be disastrous, as there is no direct cure available. I will dedicate a separate post on this in the near future.
Albert introduced another way of pruning at Pietershof that might help avoiding Esca, called ‘Sanfter Rebschnitt’ or soft vine shoot pruning. This method was invented in the 1980s by Italians Marco Simonit and Pierpaolo Sirch, after widespread vine death in their home region Friuli.
Simonit and Sirch don’t claim total innovation but revert to centuries old pruning methods. What it boils down to is keeping the vines as healthy as possible for as long as possible. Each cut into a vine is a potential opening for a disease to creep in.
With soft pruning, you only make small cuts in young wood instead of bigger cuts in older wood like with traditional pruning. The latter could damage the essential flow of juices through the vine resulting in dead parts and loss of the whole vine.
Soft pruning maintains a healthy vine conducting mechanism, healing small cuts fast, This creates less stress for the vine, making it less susceptible to diseases.
Pruning like this sounds simple, but it isn’t. Every vine needs to be assessed thoroughly to make the right cuts. It takes Pietershof longer than usual in the first years of implementing soft pruning. With the idea that vines will be stronger and more rugged, keeping trunk diseases out, it certainly seems worth the investment. And Pietershof is right up there with Giscours, Pichon-Longueville and Ramos Pinto, to name a few well known wineries in other parts of Europe that have turned to soft pruning.
Which leaves us with a huge pile of cut off wood. Burn baby burn? Nope, all wood is chopped into mulch and spread as organic cover through the vineyard. Except for the esca infected wood, this will go up in flames to avoid further infection.