Wine

Walla Walla Confronts Phylloxera

Washington’s vast appellation is battling the dreaded vineyard pest for the first time. Why are some wine producers more worried than others? 

Phylloxera. Photo credit: iStock/Yevhenii Orlov.

There are few words in the wine industry that inspire more dread than phylloxera. At its hungriest stretch in the 19th century, the forbidding aphid wiped out a large chunk of the planet’s vineyards. In France, where vineyard devastation rates reached the sobering 90 percent mark, phylloxera was dubbed a plague, a blight, a potential destroyer of wine.

Much has changed since the dark viticultural days of burying live toads beneath phylloxera-affected vines to draw out the “poison.” Many decades of winemaking later, winemakers in both the Old World and in the U.S. have come to terms with the bug, mainly thanks to the introduction of grafting vines onto valuable phylloxera-resistant rootstocks a century ago. But the bug never disappeared.

Last year, the pest was discovered for the first time in Washington’s Walla Walla Valley. Growers in the region widely held the dangerously naive belief that phylloxera simply could not exist in their vineyards, the majority of which are planted with own-rooted vines (rather than grafted to phylloxera-resistant rootstock). Now, growers are scrambling to protect these vulnerable vines, wary of cross-contamination via vineyard equipment, truck tires, or shoes. 

Walla Walla’s “Slow Spread” Theory

Napa and phylloxera know each other well. America’s most famous appellation first experienced the pest in 1881, and there have been a handful of outbreaks since then, the most notable in the late 1980s and early 1990s. At that time, amid a devastating economic recession that was already challenging growers, many growers denied the existence of the pest until it was in his or her backyard. 

But rapid viticultural experimentation ensued and, with the exception of one initial misstep with the now infamous AXR rootstock, which was found to not be totally resistant, the region succeeded in a massive vine-grafting campaign that saved the industry. By 1992, the Los Angeles Times reported, Napa and Sonoma were preparing to replant 70 percent of all resident vines, bringing a heightened sense of care and sanitation to its viticulture.

There is a prevailing sentiment in Walla Walla that the region will never face the devastation that Napa endured. Given the very slow outbreak of phylloxera, many believe the parasite has been around for a long time, but it’s been kept in check by brutally cold winters. Others credit the dusty, loess soils for keeping the pest away. 

Sadie Drury. Photo by Emily Poole.

Sadie Drury, the general manager of North Slope Management, which looks after Seven Hills Vineyard, among the oldest in the region, reports that the current mood in the valley is fairly optimistic. Winemakers are communicating with each other often and sharing their findings. “We know phylloxera is around, but we think it’s been around for a while, which hopefully means the spread and decline is slow,” she says. 

Precautions are, however, very much in the works. Growers have issued sanitation protocols and such area trade organizations as the Walla Walla Valley Wine Alliance have been proactive, facilitating meetings on the subject and relying on accrued knowledge and learned safety measures. Drury notes that there are misconceptions about phylloxera’s spread, and there’s a lot the industry does not know. “Because we’ve only known that phylloxera exists in the state since last August, we don’t know how many life cycles the pest has had,” she says. “We also don’t know where and how it overwinters, where it comes from, or how widespread it is.”

Drury says the phylloxera riddle was solved a century ago with the advent of rootstocks, and Walla Walla growers can take their time to convert their vineyards. “If the spread and decline is slow, like we think, growers can intelligently replant over the next 10 to 20 years. We can take what we’ve learned over the last 30 years and improve on matching site to varietal and clone.” 

Others are Ringing Alarm Bells

Yet some vintners are far more concerned, advocating a more urgent response to the pest’s discovery. As climate change encroaches, Walla Walla’s typically harsh winters are becoming milder, which many believe will give certain pests a better chance of survival. Brooke Robertson is the director of winegrowing at Delmas, also in Walla Walla. She oversees her family’s SJR Vineyard in the distinctive Rocks District of Milton-Freewater AVA. So far, there are no signs of phylloxera at the estate, but Robertson is pushing for a better reaction from area producers.

When phylloxera was first discovered, “the prevailing message was quite ambiguous, and it was difficult to cipher through the fearmongering,” Robertson says. “Was it valley wide? Across soil types and AVAs?” She reports that since the discovery, area growers have tested their sites, either through visual assessment or by sending samples to the lab. But there’s still no top-down system for the industry, meaning that some growers are devising their own protocols and others are not. “I believe that if we, as a valley, collectively commit to testing all vineyards in our area and impose our own version of what Australia has already laid out for us in terms of protocol, we could potentially arrest the spread of this pest.”

Robertson is referring to Australia’s highly effective quarantine protocol, which began in 2009, when growers effectively eradicated phylloxera through extensive quarantines. She says the protocols, which are rigorous and transparent, establish a baseline growers elsewhere can follow, both for vineyards that have had an outbreak and those in the area looking to keep it at bay. 

Brad Sorensen, vineyard manager at Les Collines Vineyard, also worries about the lack of a unified response. “It seems each grower is approaching the problem in their own way. There is much less oversight and regulation than I experienced down in Napa and Sonoma,” he reports. “When dealing with an invasive or new pest, an organized approach is the best way to successfully get it under control.”

Les Collines’ proactive response strategy, which includes limited visitor traffic and disinfecting boots, will protect not just its own vineyards, but also “serve as an example to what can be done in a short amount of time with minimal disruption to operations while not inconveniencing winemakers or winery staff,” Sorensen says. One welcome side effect, he adds: “We have far less airborne dust being kicked up by fast-moving trucks and cars and have seen a significant reduction in damaging spider mite populations.”

Robertson, too, reminds fellow growers that it’s not just about the current phylloxera threat. Napa Valley was successful in eradicating European grapevine moth about a decade ago, through cooperation, research, education, and collaboration between local and federal government.

“Just because we don’t have certain pests right now does not mean that they will not come here eventually,” she says. “We will likely see red blotch at some point, just like we will likely see fanleaf, Pierce’s disease, among others.”

Robertson believes there’s still hope for Walla Walla’s vines, provided there’s an organized community initiative and growers stop burying their heads in the sand. “It’s a good lesson that no matter what, nature will have its way,” Robertson says. “It’s our own hubris that got us into this situation—resting on our laurels and not actively testing for a pest that we all know can devastate our industry.”

Mark Stock is a writer from Portland, Oregon, who is now based there. He spent a decade making, selling, and cleaning up wine in the Willamette Valley in between penning stories for a host of regional and national outlets. He adores Iceland, brown trout, aquavit, and grunge rock.

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