Syracuse, N.Y.—With summer temperatures that exceed 100° F and winters known for deadly freezes, growing grapes east of the Rocky Mountains has its fair share of challenges. On March 19, the final day of the Eastern Winery Exposition, two viticulture specialists shared their thoughts about an even more risky proposition: growing grapes organically in the east.

Jens Gemmrich, owner and winemaker at 4,000-case Frogpond Farm Organic Winery in Niagara-on-the-Lake, Ontario, told the audience that organic growing is not just a farming practice, “It involves your whole lifestyle.”

For one thing, the winemaker says, organic growing involves a lot more manual labor, such as hoeing for weed control and leafing to open up the canopy rather than spraying. Such labor can create local jobs, which is positive, but the expense has to be made up for elsewhere.

“You need to achieve a fair retail price (for your wine), because it will cost you more” to grow the grapes, Gemmrich said of adhering to organic practices. For vineyard owners, Gemmrich suggested asking 20% to 25% more for organically grown fruit.

One of the main concerns the Ontario winemaker has heard from grapegrowers considering organic viticulture is the possibility of reduced yields. That concern is valid, says Gemmrich, who pointed to a study from researchers in the Netherlands who found organic vineyards produce 78% the yields of conventionally farmed vineyards. “You can technically push an acre organically to pretty high yields, but you’re going to run into health problems in your vineyard,” he said.

One of the main concerns the Ontario winemaker has heard from grapegrowers considering organic viticulture is the possibility of reduced yields—a fear he says is valid. “You can technically push an acre organically to pretty high yields, but you’re going to run into health problems in your vineyard,” he said.

Solving common vineyard health issues is also more complicated in the East. Gemmrich cited a problem with leafhoppers in his own vineyard that has been building for the past few years. “I am not sure what changed that it keeps creeping up on me,” he told attendees at EWE. “As a conventional farmer the solution is easy: You spray your pesticides. As an organic farmer, I have to find the cause.”

Fighting fungus
Under the right growing conditions (damp with temperatures of 75° or above), downy mildew needs only an hour to establish itself on grapevines. Part of identifying such problems is spending more time in the vineyard, Gemmrich said.

“When you see something happening, and you realize there’s a problem, try to get rid of it before it establishes itself,” he advised. “Organic farming requires a lot more attention. You have to be out there in your vineyard.”

Plant pathologist Bryan Hed of Penn State has been researching organic growing at the agricultural experiment station for about 10 years.

“You’re going to have to rely a lot more on cultural controls in organics,” Hed said, adding that organic growing permits the use of oils, sulfur, copper, potassium and sodium bicarbonate to fight fungal diseases. “The mid-Atlantic is ground zero for grape pathogens.”

For wine grape growers intent on adhering to organic growing practices, the first step is selecting a site. In the United States, Hed estimated, 99% of organic grape acreage is in California, Washington or Oregon, where black rot, downy mildew and phomopsis aren’t as prevalent.

East of the Rockies, on the other hand, Hed recommended choosing a site with air movement and sun. “Don’t even think about growing grapes in the shade,” he said. Black rot can take hold in the shady areas to such an extent that it will start to take hold of sun-drenched vines as well.

Choosing a site with good nutrition also is important, though Hed warns against overly vigorous soils. Finally, pay attention to neighboring vineyards: Their problems can easily spread to your vines.

For Gemmrich’s organically farmed vineyard in Ontario, he designates three rows as the pathway between his neighbor’s vineyard and his own Frogpond Farm. Even though they are farmed the same way as the rest of his vines, he sells fruit from these vines to other wineries as “conventional grapes.”

Once the vineyard site has been settled, the next step is cultivar selection. Vidal Blanc, Traminette, Elvira and Cayuga demonstrate good resistance to black rot (the Achilles’ heel of the organic grower, according to Hed), while trying to grow vinifera in the south will likely be an exercise in frustration. “Muscadine is a much better idea than trying to grow Chardonnay in North Carolina,” Hed said.

Black rot affects immature green fruit, he said, emphasizing the importance of removing diseased clusters from the trellis as quickly as possible. “Soon it will be a spore-producing factory.…It can be devastating. Very disruptive.”

To that end, Hed also advocated cane-pruning systems that remove old wood, which makes a perfect breeding ground for disease.

The researcher suggested powdery mildew is likely the most prevalent grapevine disease worldwide, and sun is its No. 1 enemy. It is also easy to control with applications of oils and sulfur, Hed said.