ELGIN, MINN. – The closest a Minnesotan can get to an invincible summer might be found inside Pam Benike's insulated hoop barn near Rochester.
Inside the barn, which stretches the length of a hockey rink, grow green vegetables — red spinach, Bok choy, radishes — while a balmy 65 degrees or more prevails. On frigid nights, the thin parallel rows are covered with white plastic tarps. The nose-tingling aroma of summer hovers as the only sound is the slow drip from an elevated drainage pipe.
"This is how we grow vegetables up here," said Benike, who runs Prairie Hollow Farm with her family. There's no artificial heating, just insulated plastic walls and sunshine. "The ground is a heat sink."
Benike bent down to put her forefinger into the soil. Just outside, the temperature was subzero. A bright sun beat down. The 52-degree dirt allows her to grow cool season vegetables she sells all over Minnesota, including the Mill City Farmers Market in downtown Minneapolis.
"Take care of the soil, and it'll always take care of you," she said, repeating a line her grandfather used to tell her.

Most northland farmers fill grain bins with harvest in the fall and end fieldwork in the frigid winter. Maybe the dairy operator outside Milaca milks cows, cold temperatures visible in cows' exhaust. The cattle rancher west of Luverne brings hay to her herd.
But a number of Minnesota agriculturalists stay busy in their fields. According to the U.S. Department of Agriculture quinquennial census, revenue from produce in Minnesota "grown under glass or other protection" doubled from $13 million in 2012 to $26 million in 2017.
To grow green plants for food in the frozen ground of Minnesota is a hardy business — and still a rare endeavor. A coterie of greenhouses — veteran hydroponics and aeroponics companies — raise fresh greens in Minnesota's dormant months. And there are places like Prairie Hollow Farm, where insulated hoop barns allow farming on plain old Minnesota soil.