Fresh Food all Winter

As winter farmers markets open for the season, you might be wondering how those tender greens were grown during some of the coldest months of the year. Over the past several years, more local farmers have been using tools and techniques to extend the growing season, making fresh lettuce and greens available through most of the winter. 

“We started to notice that there were more and more things that were carrying deep into the winter,” says Melissa Harwin from Highgate Farm in Madison County, North Carolina. “We decided we would be more intentional about it, so last year we started with our first winter market.

This winter, Melissa Harwin and her farming partner John Kunkle are growing lettuce, several varieties of kale, turnips, swiss chard, and much more. They grow some of the heartier vegetables outside in the field, but the most tender greens would struggle to survive the cold temperatures, so they’re growing them inside caterpillar tunnels that warm the air and soil.

Caterpillar tunnels might look similar to greenhouses, but they are lightweight movable structures. Farmers hammer rebar or other sturdy anchors into the ground, attach hoops that arc over the soil, and stretch plastic covers over the hoops. The tunnels’ texture and shape are reminiscent of a caterpillar, hence the name. The vegetables are grown directly in the soil and the tunnel protects them from wind, snow, and severe drops in temperature. 

Hoop houses and high tunnels use similar principles to protect produce from the elements. High tunnels are sturdier structures that usually have steel pipe frames which are covered with layers of greenhouse-grade plastic. 

Craig Mauney, a NC Cooperative Extension agent who specializes in vegetable and fruit production, recently led a series of workshops on high tunnels. These high tunnels were untapped resources for farmers in the Far West region of North Carolina who wanted to extend their growing season. 

“Some of the farmers could do year-round production with certain crops that are cold hardy, like greens, broccoli, and cauliflower, for the winter market,” he says.

Varieties that grow well outdoors don’t always succeed in high tunnels, so as part of the workshop series, they’re documenting the varieties that thrive.

“We realized that there isn’t good literature about what the varieties are, so we’ve asked two of the specialists to go through their notes for the last two years, and we’re going to send out the varieties of vegetables that do good in our region of Western North Carolina in high tunnels,” he says.

This information will be especially helpful for farms that are deciding what to grow during their first few years of winter production. Highgate Farm saw the financial impact of extending their growing season during their first year at winter markets.

“There is a lot less competition in the winter, which means that the markets are wide open for us. So last year we did our first winter market and it was just a once a week market and our sales at those winter markets last year were comparable to our very best mid-season markets because there was a minimal amount of competition,” she says.

At the same time, there are risks to growing in the winter. A few inches of wet snow could collapse a caterpillar tunnel; a severe cold snap could damage tender crops inside. There are more daily tasks for some farmers, like covering field crops at night and taking off row covers in the morning. 

These efforts are paying off as customers line up for vegetables at winter markets. As more farmers extend their growing seasons, Melissa says we could expect some new produce to appear at markets.

“Farmers who are growing through the winter will be experimenting, so you may get surprised to go to market and find celery or fennel or some other things that maybe we haven’t seen in the past winters,” she says. “There’s the risks associated with winter weather that can affect what the selection is, but I think folks who are willing and interested in eating with the seasons are going to be delighted with the ever expanding offerings that you’re going to see during the cold winter months in this region.”

Winter farmers markets kick off in January and run through early spring. Find the dates and hours of winter markets at

Aired: January 11, 2021

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