Viticulture Combats a “New Normal”
By Allen R. Balik
Climate change is a progressive, complex, multifaceted phenomenon with inconsistent patterns from one area to another and casting a dark shadow over vineyards worldwide. In addition to rising temperatures and severe drought (viticulture’s greatest challenges), it involves other diverse manifestations from increased rainfall, storm surge, rising sea levels, violent hurricanes and the tornados they spawn, devastating snow storms and blizzards along with an increased incidence of pests and disease throughout agriculture.
Climate change has been observed, documented and debated over the last several decades. Its effects, existence and man-made contributions are proven by the global scientific community in more than 90 percent of their exhaustive and meticulous studies. Yet, an ardent group of deniers continues to remain vocal on the subject by resisting suggested lifestyle, industrial and community changes we must enact in an effort to stem the tide.
My intention is not to debate the existence or causation of climate change. I look to science and recorded data to prove that as a given. Rather I’ll explore critical viticultural options being implemented to accommodate its deleterious effects. In a couple weeks I will follow-up with an insight into what the international wine community has launched to combat further expansion. This is truly a two-pronged battle with both efforts lending valuable contributions.
A few weeks ago, I was invited to join a webinar focused on how viticulture can adapt to climate change hosted by Dan Petroski, winemaker at Larkmead in Calistoga, in conversation with Aron Weinkauf, winemaker and vineyard manager at Spottswoode in St. Helena.
Both have been experimenting with various concepts over many years and agree on most aspects of climate change and its effects but differ somewhat on what direction to explore in Napa Valley. There’s no question that Cabernet Sauvignon is “King” in the Valley, but there may be some issues on its ability to continue (as we know it) with rising temperatures and extended drought.
To maintain Cabernet’s dominance, growers can look at various rootstocks, clones and inventive farming practices to find answers. An alternate route involves accentuating the “Napa” brand (also being explored in Bordeaux and elsewhere) with other varieties better suited to rising temperatures in an effort to produce wines at or above the quality level expected from our Valley. The good news is even while climate is changing, our diverse Napa Valley soils are not.
Both Aron and Dan are experimenting with different varieties and introducing various farming protocols that have proven advantageous over the last 20 or so years. Aron is a strong proponent of working with Cabernet Sauvignon which he feels is the “cream of Napa Valley that will always rise to the top.”
Dan is more inclined to aggressively experiment with different varieties that hail from warmer Old World growing areas and are more heat/drought tolerant. This quest is focused on supporting the Napa (not necessarily the Cabernet) brand. Both agree the ultimate answer lies somewhere in between. Here’s a glimpse at the philosophies they discussed.
Aron observes, “Variable conditions as becoming more variable and extremes becoming more extreme. Since agriculture doesn’t move as fast as the media… patience and long-term studies are [necessary].” Aron has dedicated several acres in Spottswoode’s vineyard to look at the growing potential of California’s “old blacks” like Carignan, Mourvedre, Petit Sirah and some hybrids.
In addition to multiple and significant adjustments in his farming practices, Aron maintains a strong focus on a variety of Cabernet Sauvignon clones and complementary rootstocks that have shown some adaptation to changing conditions. Currently, he has 10 different rootstocks on the property and 14 others in trials. As Cabernet vines are grafted to the rootstocks and begin to bear fruit, the weaker ones are eliminated and the emphasis remains on those showing promise.
Aron is also a strong believer in blending for added complexity in the finished wine. And even though other varieties planted to flourish in a warmer/drier climate may gain strength in Napa Valley, he envisions Cabernet as most likely remaining a significant portion of the blend while maintaining its local importance.
Dan considers, “Napa Valley as the world’s foremost viticultural leader while staying ahead of the curve with 20 plus years of vineyard experimentation on shade control, irrigation models, and a broad range of other [adaptive] regimens.”
He agrees we should continue experimentation and adopt new vineyard practices to protect Cabernet. But we must also be aware that change is advancing and it is crucial that the Napa brand remain the core of our focus regardless of what grapes go into the bottle and ultimately our glass.
On the varietal side, Dan respects Cabernet’s premier role and feels it may survive with newly adopted viticultural practices. However, he fears we may be facing “a chop at the knees” so extensive research must continue with other compatible varieties that could carry Napa Valley through the new normal ahead.
Currently, Dan has planted eight trial varieties at Larkmead and about half of those had been grown on-site at some time during the vineyard’s 125 year history. They “now warrant revisiting” for their adaptability. Others include Touriga Nacional (Portugal), Tempranillo (Spain), Aglianico (Italy) and Mourvedre (France), all originating in warmer and drier climates.
During the webinar, both Aron and Dan went into great depth on what we need to do in Napa Valley and stressed the ever-decreasing window of opportunity to realize positive results in the face of persistent climate change. We’re not alone in the world when it comes to vineyard and varietal modifications to preserve quality in the wines we enjoy, and here are a few examples:
Bordeaux remains active as well. In 2007, Château Brane-Cantenac in the Margaux appellation planted an acre of Bordeaux’s somewhat forgotten and late developing Carménère. It was first used in the warm/uneven 2011 vintage in the Grand Vin for the first time since the late 19th century. Planted acreage has now increased to 10 acres.
In 2009, an experimental planting of 52 different varietals (from Italy, Greece, Spain and Portugal) in the Pessac-Lèognan appellation was begun under the leadership the French National Institute for Agricultural Research and Bordeaux Wine Council. The aim of this continuing experiment is to maintain the character of great Bordeaux wine with varietals more acclimated to warmer temperatures.
And last year, the Bordeaux AOC and Bordeaux Supérieur districts elected to expand from the top five sanctioned varieties with seven (four red and three white) additional grapes from elsewhere that would better adapt to hotter and drier conditions. These additions have yet to receive the blessing or approval from Bordeaux’s Institut National de l'Origine et de la Qualité (INAO) before implementation can officially begin.
Australia is also encountering extreme weather events and compressed vintages. Research is being done at the University of Adelaide with grapevines from Cyprus for their drought-coping and heat-resisting qualities. Some Beaujolais vintners are considering experimentation with Syrah. And Oregon’s Willamette Valley is re-examining its long-held practices of dry farming and limited irrigation.
In addition to challenging virtually all classic wine producing regions of the world, climate change has offered new opportunities to other areas previously considered inhospitable to growing wine grapes. New Zealand’s South Island and Tasmania are experiencing success with additional varieties and southern England – a recent producer of world-class sparklers – are a few examples. Scandinavia has also surprisingly joined the winegrowing world with production from Denmark, Norway and Sweden.
Adaptation is necessary but fighting the expansion of climate change is also critical in avoiding ultimate disaster. We’ll explore some of the international wine community’s efforts on that front next time, so stay tuned.