The grape industry in Oregon’s Willamette Valley has persevered through adverse weather, fires, economic fluctuations, and multiple threats to the very vines that provide their livelihood. One of these challenges is the history of phylloxera in Willamette Valley and the destruction it has brought to some of the oldest and most revered vineyard sites.
How Phylloxera Came to Willamette Valley: From Europe to Oregon
Phylloxera, a minute insect that feeds on the roots of grapevines, first originated in North America – its eventual voyage to Europe and eventual return to American soil has sent reverberations throughout grape-growing regions globally. The inadvertent transplantation of phylloxera to Europe in the late 19th century through imported American vines devastated the European wine industry. It has been estimated that as much as 90% of European vineyards were destroyed in the course of this epidemic.
In the early 20th century, however, European vineyards found a solution by grafting their susceptible Vitis vinifera vines onto phylloxera-resistant North American rootstocks – an innovation that reignited the European wine industry. It wasn’t until many years later, in the 1960s and 1970s, that phylloxera finally found its way back across the Atlantic Ocean and into the budding vineyards of the Willamette Valley.
The Early Years: Planting Vitis Vinifera in the Willamette Valley
The first planting of European wine grapes, known as Vitis vinifera, in Willamette Valley occurred in the 1960s. Early pioneers, like David Lett of Eyrie Vineyards, believed that the region’s cool climate was suitable for producing high-quality Pinot Noir, Chardonnay, and other cool-climate grape varieties.
These early plantings were established on their own roots, without grafting – a commonly accepted practice at the time. Assumptions were made that Oregon was phylloxera-free, as no prior infestations had been reported. Unfortunately, that assumption would prove incorrect.
The Arrival of Phylloxera in the Willamette Valley
The first official detection of phylloxera in the Willamette Valley occurred in 1984 when researchers discovered the destructive insect in a Chardonnay vineyard in the Dundee Hills AVA. It is unclear exactly how phylloxera made its way to Oregon, but theories include contaminated planting materials or contaminated equipment brought from infested regions in California.
The Response: Grafting and Phylloxera-Resistant Rootstocks
The answer to the phylloxera problem was found in the same technique that saved European vineyards a century prior – grafting Vitis vinifera vines onto phylloxera-resistant American rootstocks. Once common practice in California vineyards, Oregon had to adapt quickly to implement these methods to mitigate the effects of phylloxera.
This process was neither quick nor easy, as vineyards had to be replanted on appropriate rootstocks. Over the course of several years, Oregon’s wine industry managed to transform its vineyards into phylloxera-resistant ones – a process that was slow but ultimately successful.
The Ongoing Effects of Phylloxera in Willamette Valley
Phylloxera has had lasting effects on the Willamette Valley’s wine industry. The costs of replanting vineyards and replacing lost vines were not insignificant, and some growers chose to abandon their vineyards rather than incur the costs.
In addition to the strict protocols that must be followed in order to prevent the spread of the insect, new rootstocks are being developed and tested to help growers stay ahead of the pest. Although phylloxera is an ongoing threat, it has become a manageable one for the resilient wine industry in Willamette Valley.