Wisconsin farmers find creative ways to deliver fresh produce in depths of winter

PAOLI — In late summer, when most other farms are harvesting or preparing for harvest, Snug Haven Farm is just beginning its growing season.

Situated southwest of Paoli, the farm owned and operated by Judy Hageman and Bill Warner has been a staple at the Dane County Farmers’ Market for decades, particularly at the winter market, which the couple helped start and where they are known for their “frost sweetened spinach” and other fresh produce grown in hoop houses through Wisconsin’s coldest months.

“Our season doesn’t start in the spring,” Warner said. “It starts in late August. That’s when we plant. That’s when these hoops are all empty and ready to go. That’s when we fill them back up.”

In 12 hoop houses covering a little under an acre of soil, Snug Haven grows spinach, carrots, kale, collard greens, chard and other hearty vegetables in the winter.

Fighting the cold is not the goal, Warner said, but something to be embraced. The plants are typically exposed to below-freezing temperatures overnight and then warm up during the day inside the hoop houses, which are metal-framed, rounded structures covered in plastic to trap the heat of the sun.

It’s the cold that imparts a sweet flavor to the spinach, carrots and other winter produce, as some of their starches are converted to sugar, keeping the plants’ cell walls from freezing.

“Usually our enemy — except for six weeks of the winter — is heat,” Warner, 62, said. “We try to keep everything cool enough.”

It’s uncommon for Wisconsin farmers to actively grow in the winter, said Andrew Bernhardt, an agriculture program specialist for the Department of Agriculture, Trade and Consumer Protection. But there are still plenty of farms harvesting throughout the season in a variety of setups, he said, such as hoop houses, greenhouses, and hydroponics and aquaponics facilities.

Each system has its limitations and benefits, Bernhardt said.

“It’s a challenge, obviously, to find local produce outside of the bountiful harvest season of the year,” he said. “But it’s not impossible.”

Located 3 miles from the southern shore of Lake Superior, Elsewhere Farm grows a diverse range of fruits, produce and crops across a quarter-acre market garden and a 4-acre orchard during the summer, said Clare Hintz, who also raises chickens and hogs.

A decade ago, though, Hintz realized that by starting a winter community-supported agriculture, or CSA, program she could focus full-time on farming. Now the Chicago native grows greens for salad mix, kale, chard, red celery, celeriac and parsley between December and March in a 12×24-foot greenhouse attached to her farmhouse in Bayfield County.

The greenhouse sits at around 35 degrees all winter, she said.

“It stretches out my labor, it stretches out my market. I have income coming in in the wintertime from the farm,” Hintz said. “That’s been a really critical aspect of having a diversified and successful small farm.”

Some vegetables and crops are more amenable to cold-weather growing, such as leafy greens, Bernhardt said. Others that set fruit, such as tomatoes, are not.

“There’s just going to be some plants that like the warmer temperatures,” he said. “It just doesn’t make a lot of economic sense to try to create that system to pay for the energy … and do that over the winter.”

Hintz, who holds a doctorate in sustainability education with a focus on regenerative agriculture, said there was a learning curve when she first began planting in the winter. Challenges range from figuring out the optimal time to plant to needing to shovel snow off the greenhouse roof.

And in the past 10 years, Hintz said she’s noticed a “really dramatic” shift in weather due to climate change. With warmer winters, she said, Lake Superior doesn’t freeze as much, resulting in cloudier days that necessitate supplemental heating of the greenhouse.

“Farmers are on the front lines of climate change,” the 47-year-old Hintz said. “We’re going to have to produce more of our food locally. And winter production, if we can do it in northern Wisconsin, you guys can absolutely do it in Madison.”

It’s unclear how much is harvested in the winter in Wisconsin as neither DATCP nor the U.S. Department of Agriculture track season-specific production. While many farmers aren’t growing over winter, Bernhardt stressed it doesn’t mean they’re sitting idle.

Farmers are preparing for the coming traditional growing season, he said, or have planted cover crops on fields for the winter, which provide agricultural benefits from improving soil biology to acting as feed for livestock.

In addition to growing, long-term cold-storage options let farmers deliver Wisconsin-grown produce to tables throughout winter, Bernhardt said. That’s important in a state like Wisconsin, the third-largest producer of potatoes and carrots, which can be stored a long time over winter, he said.

Chippewa Valley Produce cold stores about 20,000 pounds each fall of carrots, potatoes, onions and Brussels sprouts grown on 5 acres of fields at its farm between Eau Claire and Menomonie.

From farm tours and trial-and-error, Shawn Bartholomew said he’s learned the tricks to keeping the produce fresh for as long as possible, such as not washing cold-stored carrots until they’re ready to be sold.

Chippewa Valley is going into its 16th summer season, but the farm also has an active presence in the winter. Bartholomew grows salad mix, basil, shiitake mushrooms and oyster mushrooms year-round under grow lights in a 1,500-sqaure-foot room in the basement of a free meal site in Eau Claire.

The mushrooms produce carbon dioxide that aids the salad mix, which are grown on vertical racks to maximize space, he said.

“It’s not a lot, but it keeps business there,” Bartholomew, 39, said. “It keeps fresh food in the community. And then on top of what we store, you have the salad mix with the potatoes, carrots and onions. Now someone’s got a worthy delivery.”

At Snug Haven, heat is used sparingly in its production.

Each hoop house has a heater, Warner said, but they’re only turned on when it’s very cold outside and clouds obscure the sun or to make it more comfortable when working.

“Heating to grow would never pay you back,” Warner said, noting there are some exceptions like high-value flowers.

Unlike greenhouses, which Warner said are oriented north-south to maximize light exposure, Snug Haven’s hoop houses — technically known as a high-tunnel system — are on an east-west alignment to capture as much heat from the southern winter sun as possible.

Chippewa Valley sells its goods at a winter farmers’ market and used to run a CSA, which is being phased out this year. The farm mainly sells to Eau Claire restaurants and co-op grocery stores, Bartholomew said. But other opportunities have come up, including a food box program for Hmong elders and sales to school districts, such as a recent delivery to the Oregon School District, he said.

“That’s the thing with local: We just do what we have to do to make things work,” Bartholomew said. “You never know what’s going to happen. You never know who’s going to buy, but you still grow. You still plan for some crop failures, but you always just hope for the best.”

Elsewhere Farm has 50 families signed up for its CSA, including 15 families who receive boxes of food in the winter. Those are packed with the fresh greens Hintz pulls from her greenhouse as well as cold-stored vegetables like carrots, turnips, rutabaga, onions and garlic.

“We need so many more people growing in the winter if we want to re-localize our food systems,” Hintz said.