During December, January and well into February, vineyard crews are busy tending to the vineyards. Even if the vines are currently dormant, there is no shortage of work, namely ground preparation for planting and pruning. I consider pruning to be the single most important operation of the year.
Recently, with the October fires in our valleys, we have seen the importance of maintaining healthy vineyards. They can provide a defensible perimeter against these unfortunate events.
However, vines sometimes get pulled as part of the life cycle of the winery. Many reasons can trigger this drastic decision. For instance, a virus could have affected the vines and reduced their production and profitability. Wine sales could be strong with certain varietals and some vines are sacrificed to make room for a new plantation of Cabernet Sauvignon or Pinot Noir. Vines could also simply be reaching old age, needing replacement by younger and more productive plants.
All of these reasons could lead to taking the bulldozer to a plot of vines and leveling the entire field. There are many discussions in the world of farming about allowing the land to rest by taking a sabbatical year in between crops. But vines are different than every other crop. Once established, in some cases they may grow for fifty to a hundred years. These pictures illustrate the aftermath of clearing a vineyard. This site will be ready for planting after the frost season is over, around May here in Napa.
From now and into February, vineyard workers are busy pruning vine after vine and acre after acre. This is a highly skilled task, mastered by only a very few. A great vineyard worker is a key position for every winery.
The Benefits of Pruning
- Pruning will determine the crop for the current season and the next season. Precise cuts made on the spurs and the canes will dictate two consecutive grape productions.
- Pruning keeps vines healthy, getting rid of dead, diseased or damaged wood.
- Pruning provides steady grape production over several decades.
- Pruning allows for and maintains open spaces between the spurs, which encourages dry and sunny conditions for the grapes to ripen.
Below you will find a diagram of the intricacy of this task.
Grapes are only produced from one-year-old wood left from last year’s pruning. Leave too little and your yield will be low and probably low in quality, as the vine will over-compensate to produce large, diluted berries. Leave too many spurs and the dilution and the volume produced will be greater than your needs. Again, the perfect ratio between spurs, buds and crop is a difficult task to achieve.
The crown has many buds that will grow during a favorable growing year. This is where the future cane-bearing fruit will be picked by the pruner.
Each cane is pruned back to between 24 and 36 inches based on the vigor of the vine. The goal is to leave 6 to 10 well-placed buds on each cane for fruit and wood production. More important than the number of canes is the quality of canes. Medium diameter, round, well-browned canes with buds about 3 to 3.5 inches are optimal. The buds should be plump and well exposed to sunlight. If the canes develop in the shade, the quality of the fruit will be compromised.
Pruning is truly an art. It sits at the top of the decision-making abilities of the winemaker or vineyard manager every single year.