Climate Change Challenges for New York Grape Growers

By Blake Jackson

Climate change presents a complex challenge for New York grape growers. While warmer winter averages might seem beneficial, new Cornell AgriTech research reveals that erratic temperature shifts in autumn and spring are disrupting grapevine growth cycles.

Warmer autumns and "false" springs interfere with the signals grapevines use to develop cold hardiness and blossom effectively, according to a study published in the Journal of Experimental Botany.

“In New York, we are right at the coldest edge that grapevines can tolerate, so as things get warmer, it’s great for the middle of winter, but it’s not great for the spring and fall, because it messes with the signaling grapes need,” said Jason Londo, associate professor in the School of Integrative Plant Science, Horticulture Section, at Cornell AgriTech. “It sets us up for the potential for some years to be wonderful and others to have very heavy damage.”

Londo and co-author Al Kovaleski examined 31 grape varieties over three years, studying the external signals and genetic pathways that trigger grapevines to shed winter defenses and bud in spring.

They discovered that wild grape varieties, adapted to harsh northern winters, bud earliest in spring, making them most susceptible to late frosts. Commercial hybrids, bred with these wild varieties, share this vulnerability.

“And this is kind of scary because for decades we’ve been breeding and planting grapes for deep midwinter hardiness, which brings along with it this trait of waking up early. But now our winters are getting warmer and more erratic, so those cultivars are more at risk for late frost damage,” he said. “We live in this very dynamic climatic region, and climate change is making it more dynamic.”

Londo advises growers to plant diverse grape varieties as a key adaptation strategy. Planting both cold-hardy and more southern varieties can create greater resilience against unpredictable weather patterns.

“The safest thing is for growers to plant diverse cultivars so that year over year, you have better resilience,” he said. This approach helps mitigate the risks associated with both warmer winters and potential polar vortex events.

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