Farm Grows Underground: How a Berkshire Farmer Banks Summer Heat to Grow Kale in January
Originally aired on WBCR-LP Great Barrington, January 17, 2022. Interview by Bill Taylor and Jaye Moscariello.
On a morning when the temperature outside had dropped to eight below zero, Jim Schultz was picking Tuscan kale, spinach, Asian greens, arugula and lettuce in a greenhouse that had no furnace running. Schultz, who owns Red Shirt Farm in Lanesborough, explained on WBCR’s farm and garden show how that’s possible: the greenhouse doesn’t burn fuel to make heat, it banks heat that’s already there.
The system is called a climate battery. Fans pull hot air from the peak of the greenhouse down through perforated pipe buried four feet under the growing beds. All summer, that surplus heat gets pushed into the soil instead of vented outside. “By the end of the summer we have a soil temperature that’s roughly in the mid to high seventies, all the way down to four feet,” Schultz said. When winter comes, the fans keep running, but now the soil is warmer than the air, so the house gets heated from underneath. On nights down to ten degrees, the banked heat alone can hold the greenhouse near 40 degrees. Below that, he runs a propane backup so the system doesn’t get exhausted trying to fight a hard cold snap.
Schultz described his growing methods as beyond organic, not because of a label but because of what the organic standard still allows. “Pesticides are killing native pollinators, our bee population, and we were opposed to that,” he said. He pointed out that even organic-approved fungicides can damage soil fungi that plants depend on. His approach instead: leave the soil alone as much as possible, keep it covered, and treat any pest or disease problem as a sign that something in the farm’s own management needs fixing, not an excuse to spray.
That thinking runs through the two acres of intensive vegetables that support a 130-family CSA, a farmers market stand, and wholesale accounts including Guido’s. Schultz builds permanent raised beds so foot traffic and equipment stay confined to the walkways, keeping the growing soil undisturbed year after year. He uses a broad fork instead of a tiller when the soil needs aerating, and he’s cut tillage down to a single event when a new bed is first broken in.
Nutrient management has been a multi-year project. Schultz started by remineralizing soil through Dan Kittredge’s Bionutrient Food Association program, then moved into plant-tissue testing through John Kempf’s methods to catch nutrient problems before they show up as disease. He credited that shift with saving a tomato crop that had been getting hit by leaf mold. “First year we started using that program, SAP Analysis, we identified some issues with phosphorus deficiency and with some foliar sprays, stopped leaf mold in its tracks,” he said. Where the disease had wiped out plants in past seasons, the tomatoes kept producing through the end of the year.
Schultz also talked about Red Shirt Farm’s partnership with Roots Rising, a Pittsfield-based program that brings high school students, some of them considered at-risk, to the farm once a week during the school year and full days in summer. The teens get paid a stipend and take on real farm labor, spreading mulch, flipping beds, seeding and harvesting crops they eventually eat. “To have this influx of really wide-eyed, enthusiastic young people onto the farm is a boon to us as well,” Schultz said.
Asked how he landed on the farm’s name, Schultz traced it back to his 26 years teaching, coaching and doing school administration before he ever started farming. “I essentially Red Shirted for 25 years waiting to start my farm,” he said, borrowing the term from athletes who sit out a year to develop before their real run begins.
Red Shirt Farm sells at its North Adams market from June through October and monthly through the winter, plus Berkshire Grown’s countywide market series. Farm tours run Sunday mornings when demand allows, and the farm is still looking for apprentices for the coming season.
