WANATAH, Ind. — Getting down in the dirt to plant lettuce, radishes, spinach and beets isn’t something that normally takes place in December, but Liz Maynard finds it quite normal.

She didn’t even mind the cold, driving rain either. That’s because Maynard, a vegetable crops specialist with Purdue University extension, was comfortably tucked away inside the new high tunnel building at Pinney-Purdue Agricultural Center, just west of Wanatah in Porter County.

Stepping inside the 30-by-48-foot plastic-covered structure was a contrast in elements. Outside it was gray, windy, wet and muddy; inside, it was cool, bright, dry and filled with the bright green of newly planted vegetables. Maynard seemed to find it difficult not to smile.

The high tunnel project (essentially an unheated greenhouse) is the newest research tool at Pinney-Purdue. The 1,640 square-foot metal frame structure is covered in durable plastic and is the first of two planned for the research center.

“There is a lot of interest in growing vegetables in unheated structures like this in the winter,” said Maynard, who pointed out the temperature outdoors was in the high 30s. Inside, it was a bit warmer – and a lot drier.

“Growing vegetables in a structure like this has gone on elsewhere for a long time,” she said. “Just the fact that we have one now where we can grow in periods that we otherwise couldn’t, gives us an opportunity to do a lot more research.”

Even though there isn’t a heater for the high-tunnel – and no air conditioner in the summer – Maynard said the structure will protect plants even when temperatures drop into the low 20s.

“This is different than a greenhouse in that respect,” she said. “We’re just covered with a layer of plastic, but if things get too cold, we can cover the plants with another layer of plastic that will help keep the heat in.”

Between each row of vegetables (each row has been planted at different intervals, starting at the end of September) is a small metal frame that allows a second plastic cover to be pulled over the plants as extra insulation on extremely cold days.

“You don’t get the effect on a day like today when it’s cloudy and rainy, but when the sun is out, it really warms up in here. It warms up the soil and the soil retains the heat overnight,” she said.

Among the vegetables growing in each row are lettuce, kale, radicchio, a variety of Asian greens (including bok choy), spinach, turnips, radishes, pea shoots, beets and mustard greens.

Maynard said more farmers across northern Indiana are planting vegetables and they bring questions to her about the optimal planting and harvest times: “I could tell them what researchers found out in other places, but now I can tell them what’s happening here.”

While there are commercial farmers who have high-tunnel structures of their own, she said they are relatively rare in Indiana, especially in the northern part of the state.

“In other countries, structures like this cover acres and acres of land,” she said. “Will it happen here? It could, but we have to consider the market and figure out whether it’s worth it.”

Unlike traditional row crops that are harvested by machine, vegetables grown under high-tunnel conditions must be planted and harvested by hand. “Still, this opens up the seasons for vegetable growers,” said Maynard.

Jon Leuck, superintendent of Pinney-Purdue, is excited about the research possibilities. 

“It took us just over three weeks to put this up. Now that we know the shortcuts because we’ve done it once, it will be easier to finish the second one.”

Leuck said it cost approximately $10,000 to put up the structure, although because of the rails, it’s one of the more expensive models. Both high tunnels are on rails that allow them to be rolled to new areas so the soil isn’t depleted by continual farming.

“This expands our research capabilities and that’s what we’re all about,” he said. “We think this is a great place for this research because farmers who are interested can learn a lot and they’re not that far from markets in Chicago and Michigan.

“At the open house we had recently, one of the people stopping by was a chef at an area restaurant. He was really interested because he said finding farm-fresh produce in the winter is difficult for him,” said Leuck. “With a high-tunnel, farmers could find a ready market for vegetables at restaurants in the area.

“We think this is a great addition to what we’re doing here. If Liz can highlight some of the keys to raising vegetables year-round, I think more folks would be interested. People who are interested in this want to see it for themselves and, with this here, now they can. It has more value to them than just reading about what’s taking place somewhere else.”

Maynard said she is fielding more questions about gardening as more people – farmers and urban dwellers alike – are looking to raise their own vegetables. Whether it’s for personal use or to sell at local markets, she said she wants the research at Pinney-Purdue to answer their questions.

“What’s great about this is that a hard freeze signals the end of the outdoor growing season, but vegetable farmers who take advantage of unheated greenhouses and row covers can protect crops into the late fall and winter for nearly year-round harvest,” she said.

“High tunnels can give producers opportunities to provide customers with fresh-picked produce long after leaves have fallen and snow is on the ground.”