Viniculture – Why do we prune the vines?

Did you know that grapes are the largest fruit crop on earth? And did you know that reaching the highest level of quality in wine is only possible by starting with the highest quality fruit? It all begins with vines and their care. What is loved most about grapevines has been their ability to adapt and grow in a wide variety of soil types, running the gamut from light sandy loam to solid clay and volcanic mountaintops.

In our winter months, it’s all about vineyard cleaning and pruning. We prune the vines because better-quality fruit will grow on vines that are pruned back to distribute the bearing wood evenly over the vines. In January and February we watch as the leaves drop and notice that the vines are empty of sap, and know that Tom Montgomery, our winemaker, has made the call to our talented vineyard crews to begin the meticulous pruning of vines almost back to their main stems. Pruning is an art and I often think of Michelangelo when pruning is being done, because if these artists do too much, it will cause small, uneconomical crops; if too little is done it will cause over-cropping and low-quality fruit – it is all in the balance. Pruning of the vines also facilitates cultivation, disease control and harvesting, especially when the vines are trained to grow in a particular shape. Our vineyard crews have skills that require experience and judgment and they do this job knowing that it cannot be done to perfection by machine. At B.R. Cohn we use two basic pruning methods, “cane-pruning” and “spur-pruning” (also known as head-pruning), with a tool referred to as a secateur or vine clipper. Spur-pruned vines are usually found in older vineyards. Spurs are the canes (or branches) trimmed back to only a pair of buds. Each bud will become a shoot which grows to a cane that bears the crop.

Walking through Olive Hill Estate’s various vineyard blocks, it is easy to identify vines with cane-pruning methods applied. You’ll see that one to four, one-year-old canes, each with six to fourteen fruit buds are trained along the trellis wires. This style is referred to as “cordon pruning”, since the vine looks like outstretched arms (cordon is French for arm). The task for the cane-pruners is to train the current fruiting canes and at the same time consider which spurs to train for next season’s fruiting canes. With the pruning finished and warm weather slipping in, the vines are awakening from their dormant state. Nature has signaled its time for sap to rise and brown sheaths which cover the buds to break away, shoots start to emerge, flowering follows and then the blossoms are replaced by minuscule berries and the birth of Vintage 2012 is ready for nurturing.