Sustainable viticulture

Different summer annuals, including sunflowers and vegetables, are planted near the grapevines at Seven Hills Vineyards to add biodiversity.

Changes made to farming practices at Seven Hills Vineyard are not only designed to improve the health of the vines and soil, but also the health of the vineyard workers. Fresh garden vegetables, grown along the vineyard edges, have a dual purpose: to increase the biodiversity of insects, animals, and plants, and to supply the workers with healthy foods during the summer. 
The newer Seven Hills Vineyard (there are two in the Walla Walla Valley with different owners), with plantings that date back to 1997, is located on the eastern edge of the Walla Walla Valley appellation in Milton-Freewater, Oregon. The vineyard, owned by three Washington State wineries—Leonetti Cellar, Pepperbridge, and L’Ecole No. 41, has about 200 acres of bearing grapes, but with the recent purchase of about 1,700 acres of an adjoining dryland wheat farm, it is poised to expand. Eighty acres of the new wheat land will be planted this year. The mainstay wine grape varieties at Seven Hills are red, although the white varieties of Semillon and Sauvignon Blanc are grown for L’Ecole No. 41.

As vineyard manager, Chris Banek has embraced Seven Hills’ philosophy of sustainable farming, and farms the vineyard as a biological system. He uses nature to combat nature and applies soft chemicals (none with long residuals) only when necessary. He credits viticultural consultant Rick Trumbull of Walla Walla for guiding Seven Hills in sustainable viticulture.

Nutrition

Banek focuses on soil health and nutrition, using compost, compost teas, and other soil improvement products such as seaweed, to build what he calls “systemic acquired resistance.” Vineyard debris, like prunings and thinned leaves and clusters, also are flailed and added back to the soil.

“If you can get the vine and soil health right, then the vine will develop, by itself, resistance to outside pressures,” he said, adding that already he’s seen improvement in their vines from pest and insect pressures.

Getting the soil and vine into nutritional balance is no easy feat, especially since most of the land was farmed for decades in dryland wheat before conversion to wine grapes. In some of the newer plantings that follow wheat, without crop rotation or time between wheat and wine grapes, soils are what he calls “dead.”

“Ideally, it is best to have two years before planting a new vineyard when following wheat,” he said. “Spring oats can be planted the first year, then followed in the fall with mustard. The mustard, a winter annual, will grow and have biomass for incorporation in the spring before planting. But once the vineyard is planted, it’s tough to make soil improvements through amendments.”

They follow a rigorous soil amendment program before planting grapes, adding compost, lime soft rock, and other nutrients.

Banek admitted that it might take up to ten years to bring soil nutrient and mineral levels in some of the vineyard blocks to where he wants them. By using compost and other soil amendments, nutrients are slowly released in the soil in amounts needed by the plant, he explained.

Improving soil tilth has also provided irrigation benefits. Adding humus and organic matter to the soil has improved water infiltration dramatically, Banek said. “Before, we could only run water in a four-hour set before we had water puddling in the vineyard. Now, we could run 24 hours if we wanted and still wouldn’t have runoff.”

They also take regular soil and foliar samples to monitor nutrient levels, Brix, pH, and electrical conductivity as indicators of nutritional balance.

In collecting the plant sap, flagged vines throughout the vineyard are sampled, with leaves collected every two weeks during the season. The leaf juice or sap is squeezed, using a press. A refractometer is used to read the sap Brix, and a meter is used to read pH and electrical conductivity. Brix measurements of 12 and above are considered good levels indicating nutritional balance.

“We have seen an increase in Brix after some foliar feeds,” he said, but added that they haven’t seen a spike in pH or electrical conductivity.

One area of sustainability that visibly demonstrates the changes that have taken place at Seven Hills is biodiversity. Biodiversity is an important component under the certification program offered by the Walla Walla Valley wine grape sustainable program called Vinea. Banek has used cover crops down the vineyard rows and flower and vegetable gardens along the vineyard borders to add diversity to the monoculture of wine grapes.

When Banek noticed that alfalfa grew by itself in parts of the vineyard, he began planting an alfalfa/grass mix for the cover crop down row middles. “The deep-rooted alfalfa survives well on a grape water diet, and its blooms attract insects,” he said.

Biodiversity

Vegetable gardens planted near the vineyard borders also add biodiversity, providing a pollen source for beneficial insects, controlling weeds, and aiding in dust and erosion control. The bright, colorful, summer vegetable garden is productive into the fall with corn, pumpkins, and other vegetables.

“We do gardens not only because they look nice and add plant diversity, but because there are employee benefits as well,” Banek said, adding that the gardens provide employees with healthy foods in the summer. “We’re supplying a healthy, nutrient-dense food source for our employees.”

Wild, native roses and lavender are examples of perennial plants they use to attract parasitic wasps and other predators and build a diverse plant population near the vineyards.

Last year, they bought $50 worth of annual flower seeds from a local dollar store and spread the seeds throughout the vineyard edges. Water was available to keep the flowers growing throughout the season. They double seeded—seeding the flowers in spring and again later in the season—to enjoy flowers continually during the summer and fall months. In the fall, they harvested the flower seeds and now have more than several years worth of seed saved for future plantings.

“The flowers didn’t cost much,” he said, adding that they required little effort other than some weeding and watering.

Since making a concerted effort to add diverse plant species to the area, he has seen more beneficial spiders in the vineyard, and the rows seem “more alive” with insects.

“It’s a long process to achieve sustainability, and you have to focus steadily on the objectives,” Banek said. “But it’s getting easier.”

“It’s all about leaving the soil in better shape for my kids and the next generation,” Banek said. “It’s about the minimal use of chemicals and not using any long-residual pesticides. Sustainable viticulture definitely makes a statement when it comes to environmental practices in the vineyard.”