On Monday, we moved our greenhouses. This event, which we do every fall, is at the center of our winter crop production. The spinach we will harvest for the next CSA box was planted during the heat of mid-September, when tomatoes were still growing in the greenhouses. As the length of the days decreases, crop growth slows to a crawl. The tomatoes still produce using energy stored in the plant, but tender greens can only grow with the light of the sun. To counteract the slowing growth, we have to plant early and follow a precise schedule to insure a good supply of greens throughout the winter.
We don’t heat our winter greenhouses (except for one, that we keep at 32 degrees, to keep our rosemary alive). Instead, we rely on the sun’s warmth during the winter days and a selection of hardy crops to survive the winter’s cold. By early December, the temperature falls below freezing every night in the greenhouses, but we have selected crops that can handle the harsher weather with a little bit of protection.
By having the crops out of doors throughout the fall, they have a chance to harden off to the cold days to come. Inside of the greenhouse, sunny days turn quite warm, and would produce lush, tender growth. The first cold snap of early fall would turn them to mush inside the greenhouse. By hardening the crops out of doors, we prepare them for the harsh reality of winter.
So every fall, we pull the greenhouses over the growing crops. Don, from Don’s Towing in Decorah, drives out with his very shiny dual winch tow truck (I want one!) and parks at the far end of the salad beds from the greenhouse. We undo the anchors that hold the greenhouse in place, hook up the winch cables, and slowly and carefully reel it in. Two people with heavy pry bars steer the greenhouse, which is mounted on skis. It takes about a twenty minutes to move 100 feet—but you have to be careful with a 3,000 square foot building!
Tucking in the winter salad begins the process of putting the farm to bed for the winter. Due to the sketchy October weather, we moved the greenhouses late this year. Over the next few weeks we will mulch the garlic and herbs, clean up the tools and tractor implements, and batten down the hatches for the long night of winter.

