The Emergence of Phylloxera in Napa Valley

Introduction: The History of Napa Valley and Phylloxera

Even though there is historical evidence that a large number of wild grapes were native to Napa Valley, the region’s potential for producing wine grapes was not realized until a pioneer by the name of George Calvert Yount started a grapes plantation. In 1839, Yount founded one of the first homesteads in the valley. He is also credited with being the first person to grow grapes in Napa Valley. Soon after him, other pioneers, such as John Patchett and Hamilton Walker Crabb, played an important role in introducing the first Vitis vinifera grapes to the valley.

The history of Napa Valley’s success in winemaking is one of toil and adversity, even though the region is famous for its wine and is considered a mecca for those who appreciate the finest wine. In the 1800s, a pest infestation named Phylloxera originated in the United States and hitchhiked its way to Europe. The pest came perilously close to wiping out all the European vineyards. In the beginning, after its infestation on the East Coast of the United States, Phylloxera made its way west to California, where it first appeared in the 1860s.

Botanist Dr. Andrew Walker believes that the pest “came with the westward expansion from the East,” and he bases this theory on historical evidence. Around the same time, it also found its way to Europe through the import of nurseries, plant materials, or other organic debris from the United States. It was analyzed at the time that Phylloxera only infected vinifera grape types; it did not affect the American rootstock species Vitis rupestris, riparian, or Lambrusco, which were resistant to the pest.


Phylloxera in Napa Valley

The Infected vinifera

Emergence of Phylloxera

A winegrower named John Baritelle from the Napa Valley was taken aback when he found that one of his vineyards had four stunted vines. The following year, the number increased to sixteen, and Baritelle was worried about the situation due to this development. His worries were due to the fact that he could not find a concrete cause that the plants were unwell. By the 82nd season, the number of infected vines had substantially grown, prompting Baritelle, who was already worried about the situation.

He decided to seek a visit from vine specialists from the Davis campus of the University of California, which is situated nearby. The specialist accepted his request. Their collaboration and hard efforts resulted in pioneering in the provision of alternative solutions or practices that can help in not only identifying the root cause of stunted vines but also reducing the spread of Phylloxera problem.

Phylloxera in Napa Valley

The Phylloxera

In the 1860s, agricultural experts from the University of California recommended using a rootstock called AxR1, which was known to be resistant to Phylloxera and produce large quantity grapes. This recommendation was practiced long before Phylloxera became a major problem in the valley. Most growers in Napa Valley and the rest of California quickly switched to AxR1 from St. George grape variety. St. George was a native American rootstock noted for having a lower yield and less productivity overall. During the  1870s, it was also planted by the vast majority of brand-new vineyards established in California. However, after a few years, vines growing in Napa Valley on AxR1 roots started showing indications of sickness.

In 1883, researchers made the groundbreaking finding that Phylloxera was the agent responsible for the disease. The replanting of vineyards in Northern California cost the wine industry more than half a billion dollars, which was spent more than that amount. Since it began conducting its tests with a wide range of different rootstocks in 1883, the Robert Mondavi Winery is estimated to have spent fifty million dollars on redeveloping its phylloxera-affected vines. This estimate is based on how much money has been spent.

The Phylloxera and the root effect

The evident and urgent course of action suggested was the removal of the infestation by using pesticides or through floods, which would have caused the pest to drown and die. On the other hand, grafting was considered to be a more academically sound and long-term option; however, by considering the vast quantity of American vines in Napa Valley and California, the vine growers concluded that grafting was necessary.

Although in 1884, the expert realized that the amount of effort and time that was required to graft these new vines in the valley and also in the European vineyard is impossible.

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Key Dates to the Emergence of Phylloxera

November 4, 1839: Settler George Yount was the first to plant grapes in Napa Valley.

November 2, 1860: On this day, the Phylloxera pest made its first appearance on the West Coast of the United States in the state of California. Before this day, the Phylloxera pest had been born and nurtured on the United States East Coast. The local vines were resistant to the pest.

June 12, 1861: On this day, Charles Krug established the first winery in Napa Valley that was used commercially. Over the following 20 years, many other wineries opened their doors for business. Many of these wineries remain operational today, such as Beringer Vineyards, Schramsberg Vineyards, and Inglenook.

August 5, 1868: This was the day when Jules-Emile Planchon and Gaston Bazille discovered the little beetle that they later termed “devastator,” Phylloxera Vastarix.

April 4, 1870: On this day, the European rootstocks reached California to examine which would work better in the region. After this period, many trials and tests were conducted to ascertain the solution to Phylloxera.

January 23, 1872: On this day, a prize was made to find the cure and solution to the Phylloxera problem in the valley.

February 13, 1890: The Napa Valley was stricken with an epidemic of the root louse phylloxera.

Want to read more? Try these books!

California's Napa Valley- One Hundred Sixty Years of Wine Making Phylloxera- How Wine was Saved for the World


J’nai Gather, “Phylloxera In Napa Valley: Then and Now,” (Wine Enthusiast).

Categories: Phylloxera, This Day in Wine History | ArticlesTags: , , , , By Published On: October 21, 2022Last Updated: February 21, 2024

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