The Art of Vine Pruning: Getting Schooled in Lake County, California

By John Szabo, MS

John Szabo Pruning Cabernet sauvignon in the Beckstoffer Crimson Ridge Vineyard, Lake County, under the watchful eyes of Jacopo Miolo of Simonit & Sirch. Credit: Nathan DeHart for Lake County Winegrape Commission

The most critical vineyard action takes place in the dormant season: pruning. Get it wrong, and your production drops at best. At worst, you shorten the life of a vine and compromise wine quality, while also causing yourself more work in the summer. This past December I took a trip down to Lake County, California, to attend a two-day course on pruning, hosted by the Lake County Winegrape Commission and run by Simonit & Sirch, an Italian duo of “vine master pruners”, to get a first-hand look at how to properly prune a vine.

Read Why Proper Pruning is So Essential

It seemed to me a curious niche business at first, but Marco Simonit and Pier Paolo Sirch, both native northern Italians, have caused more than a small ripple in the wine world with their consultancy and teaching academy based on the rigorous pruning methods they have been developing for years. Many of the world’s top wineries employ them, from Champagne houses to super Tuscan Estates, Bordeaux Cru Classés, Burgundy legends, and cult Napa Valley producers, to list just a few regions. It’s not so niche after all, and there is real demand for this type of expertise, much of which has been lost in an era of industrial viticulture.

At stake is nothing less than the health and longevity of a grape vine. The first part is obvious: healthy vines are more disease and climate resistant and produce higher quality grapes. But the second is no less critical. Old vines are widely considered to produce better wines (naturally balanced, concentrated, complex), and are also less affected by radical vintage variation. Perhaps even more importantly, extending the useful lifespan of a vineyard can save a winery hundreds of thousands of dollars in replanting costs. Rather than having to replace sick and dying vines after just 25 or 30 years, properly pruned vines can remain productive for a century or more. In this era of sustainability and resilience, it’s a huge a win-win for everyone.

Some of the oldest cabernet Sauvignon vines in the world growing untrellised, planted in the 19th century,
Louis Martini’s Monte Rosso vineyard, Sonoma County. Credit: John Szabo, Volcanic Wines.

At the heart of the Simonit & Sirch method are a handful of logical dictums. At the top of the list is simply allowing the vine to do what it wants to do, which is grow. This might not seem so radical, but modern viticulture aims at fitting the vine to the trellising system, rather than fitting the trellising system to the vine. And this does take a radical mental shift. You’ve been in a vineyard and seen the posts and the wires used to confine grapevines and make vineyard work easier. Simonit and Sirch argue that pruning to incrementally increase vine size each year is much better for the plant. More wood means more carbohydrate reserves, more energy, more resilience, compared to making regular, large cuts to contain the vine in a limited space. This may require eventually adjusting the trellis system to accommodate the larger vines, but that’s easier, and cheaper, to do than replant. It’s not coincidental that most of the world’s oldest vines are minimally pruned like bush vines, allowed to slowly gain size over a century or more. (See photos above and below.)

Pier Paolo Sirch with the oldest known Fiano vine, 200+ years, in Lapio, Campania, growing practically wild. Credit: John Szabo, Volcanic Wines.

Smaller cuts also mean smaller wounds in the vines, another pillar of the S&S strategy. The larger the pruning wound – think of cutting off an arm vs. a finger – the higher the chances of introducing fungal vine diseases like Eutypa and Esca. These are spread when ambient fungal spores land on an open wound, most often a pruning cut. The fungus then grows, slowly killing woody tissue and reducing sap flow, eventually killing the vine. Trunk diseases like these are a massive problem worldwide and appear to be on the rise. It’s estimated that over 10% of the world’s vines are affected.

Big pruning wounds close to the trunk opening the door for fungal disease and restricting sap flow. Credit: Jaime Good, wineanorak.com

Leaving spare wood, that is, not pruning right back to the main trunks or arms but rather leaving a few extra centimeters between the cut and the perennial wood, also helps to maintain the vine’s sap flow. Each time a cut is made, a ‘desiccation cone’ forms, expanding inward from the cut as the vine seeks to protect itself and close the wound. A conical-shaped area dries out and creates dead wood through which nothing flows. Although it looks less tidy to prune long, pruning too short causes the desiccation cone to form inward into the main arteries of the vine, restricting or stopping sap flow. Oversized or multiple desiccation cones can also eventually kill a vine, at least certainly reduce its lifespan.

Simonit & Sirch: desiccation cones

Admittedly, it’s not easy for someone who has been pruning a certain way for a decade or more to absorb and adapt the Simonit & Sirch methodology. And it’s also true that every vineyard needs to be considered individually, with techniques adapted to specific conditions and desired outcomes. There’s no one-size-fits-all approach to grapegrowing. But the basic principles still apply universally. It’s a smart move by the Lake County Winegrape Commission to host the Simonit and Sirch pruning school to teach growers how best to manage pruning.

John Szabo Pruning Cabernet sauvignon in the Beckstoffer Crimson Ridge Vineyard, Lake County, under the watchful eyes of Jacopo Miolo of Simonit & Sirch.Credit: Nathan DeHart for Lake County Winegrape Commission