Before I’d ever stepped foot into a vineyard, I can honestly say that I had no idea vines required so much attention all year round. I guess I just figured that most of the outdoor work happened during harvest or planting season and outside of that the vines just did their thing…
Ha! How wrong I was!
This article will focus on winter pruning. This is just one of a wine-grower’s several winter tasks, but it’s one of utmost importance that requires extended training (and a lot of time spent out in the cold!).
For more insight on what happens during the rest of the year, be sure to check out my articles on bud-break, spring, and harvest.
Pruning is done during the cold winter months while the plants are dormant. The purpose is to increase the amount of 1 year old wood on each vine and cut off as much of the old wood as possible. Why? Because fruit is only produced on the shoots of 1 year old wood, or canes. Anything older will only produce leaves and grape-less shoots. That means that by cutting back as much old wood as possible, a winemaker is able to increase new growth in the spring.
In winemaking, though, it’s certainly not all about quantity. There are regulations in place that limit the amount of wine allowed to be produced from a certain surface area of vineyard. This is referred to as yield-control and it’s main purpose is to control quality levels, depending on the location of a specific vineyard site or group of vineyards world-wide. For example: within the AOC of Hermitage in France’s Northern Rhône region, winemakers are limited to producing 40 hectolitres of wine per 1 hectare of vineyard area for red wines, and 45 hL/ha for whites.
Yield control is really important when it comes to making quality wine because vines that produce too many grape clusters will become exhausted and unable to properly nourish their fruit. The result: grapes with less concentration leading to out of balance wines.
An old vine, for example, will naturally produce very concentrated fruit compared to an untended younger one because it’s output of grape clusters is lower. The little bit of fruit it produces will, therefore, be higher in concentration and flavour. That’s why it’s especially important for quality-focused growers to cut back the younger, more vigorous vines in the winter. But in the end, it’s all about finding a vine’s balance.
Why is it important to prune while the vines are dormant?
Pruning too early can stimulate new growth, which likely won’t harden up in-time for the cold weather. By late winter the vines are in full chill-out mode and not a lot goes on within them. Other than a bit of root growth (if the soil temperature isn’t too low) the vine is basically just hibernating until spring. The roots will have taken up enough nutrients post-harvest to store as energy and use to develop shoots when spring arrives.
Vines aren’t the only thing in a vineyard that are dormant in the late winter months. So are most diseases and insects that could otherwise invade or infest cuts made in the wood during pruning.
It’s also just a lot easier to see what you’re doing after the leaves have dropped!