UNH researchers identify which radicchio varieties can thrive in New England

You might notice a vegetable with unusual pink leaves at farmers markets this fall. While often mistaken for cabbage or lettuce, the culprit is actually radicchio, which is native to Italy.

For local farmers, the crop offers an opportunity to stand out from the crowd. Radicchio is increasing in popularity amongst consumers and restaurants for its unique color, flavor and health benefits. But researchers say there’s still a lot to learn about its performance in New England.

University of New Hampshire researchers examined over thirty varieties of radicchio to learn how farmers in the region can grow the leafy green.

Becky Sideman is a professor of agriculture, nutrition and food systems at UNH and lead author of the study. She said that the crop makes for interesting research due to its genetic variability.

“It’s got more diversity in it than pretty much any other vegetable crop I can think of,” Sideman said. There’s all these types and colors, and they’re used for different culinary purposes.”

Some varieties of radicchio can be easily impacted by climate conditions. Under heat and other sources of stress, the vegetable can see bolting, early flowering that increases bitterness, or tip burn, a form of rotting at the edges. In New England, it’s typical for less than half of radicchio plants to become marketable heads, according to the UNH study.

For Sideman and her team, it’s important to understand which radicchio varieties produce the greatest number of marketable heads consistently. The unusual dry growing season of 2022 and extreme wet conditions in 2023 allowed researchers to see how the crop fared under a variety of stressors.

“One thing that was kind of exciting for us to see is that some varieties were really consistent in their performance between those two years,” she said. “It’s early to tell, but that suggests that they might be able to take what the climate throws at them a little better than maybe some varieties or some crops.”

The study’s results found that amongst seven main radicchio types, the chioggia type and varieties had the best marketability in combination with disease resistance.

This is the type of radicchio most familiar to consumers, with its traditional red coloring.

Sideman and her team plan to continue their research on radicchio this fall, and hope to better understand how planting times will impact the plant’s harvest window.