Researchers at the University of New Hampshire are studying eight grape varieties to see which are best suited for growing in the state and in much of the rest of New England.

Extension professor of sustainable horticulture production Becky Sideman and extension field specialist George Hamilton are evaluating the canadice, concord seedless, lakemont, marquis, mars, reliance, thomcord and vanessa varieties, according to a news release.

“Seedless table grapes are typically grown in much warmer climates, although several newer varieties released since the 1970s promise increased winter hardiness,” Sideman said in the release. “George Hamilton collaborated with vineyard owner John Lastowka in Merrimack to conduct a preliminary trial, and the best varieties in their experiment were selected for the UNH research vineyard.”

Three varieties — thomcord, lakemont and marquis — have demonstrated some winter mortality and poor vigor, and those varieties also proved susceptible to various diseases. Downy mildew most affected lakemont, thomcord and marquis, and marquis also had some issues with powdery mildew and with anthracnose.

Varieties canadice, concord seedless and mars appeared to fare best across the board, according to the preliminary results of the research. More details can be found at

The research is being funded by the New Hampshire Agricultural Experiment Station and is designed to help regional growers wanting to produce table grapes for local markets.