Cold Frames, Greenhouses, and Beyond: Four-Season Gardening

Enlarge Image Image Gallery Digging in during the winter months. iStockphoto.com/Simon Howden

Learning to garden in four seasons – rather than one (summer) and fragments of two (spring and fall) – can be a bit like learning to think in four or five dimensions. But the rewards, say Colorado gardeners Rick and Shirley Visser, are mind-boggling abundance: fresh salads in December, carrots in February, spinach in March, and a whole new appreciation of what’s possible.

“Some people want to plant a garden and have it over with. But I’ve had more produce in fall than I’ve ever had in summer,” Visser says.

For Adam Montri, who, with his wife, Dru, and young daughter, Lydia, runs Ten Hens Farm in Bath, Michigan, the difference a high-tunnel hoop house made on their farm was the ability to reap an income year-round rather than just for the summer season.

In his job educating about hoop houses, a joint project of Michigan Food and Farming Systems and Michigan State University, Montri also noticed a less tangible, but infinitely richer, change.

“You always get a community growing around the farmers’ markets,” he says. “This makes that com-munity happen year-round.”

For many farmers in the upper two-thirds of North America, planting under cover – whether that cover is as minimal as compost-heated planting beds with floating row covers or as intricate as a 30-by-90-foot greenhouse erected over cherry trees – can alter an operation’s destiny and the farmer’s relationship with the land.

The Vissers became four-season gardeners – a term they coined in tribute to Eliot Coleman’s groundbreaking 1992 book, Four-Season Harvest – when they moved from a higher elevation down to Longmont, a town outside Boulder, Colorado. Another daughter was selling her small, turn-of-the-century home with an extra-deep lot, and Rick had long craved the space, soil and less harsh climate. When remodelers came to make changes to the house and make his garage an art studio, he had them rework the yard as well – incorporating six raised beds, a mini-orchard and composting area, and two sheds. Soon after, he built a cold frame to the specifications in Coleman’s book.

That cold frame is now Visser’s pride and joy, much more so than a small kit greenhouse he attached to the warm west side of one of the garden sheds. Between the two, he’s able to grow sturdy tomato seedlings that germinate in the home’s basement and produce a crop of low-growing vegetables that feed the couple through the entire winter. The cold frame’s low height – only 6 to 10 inches above the ground, with interior soil levels below that – is sufficient to keep his crops growing. And the operation is low maintenance: He props each pane of glass up with a notched 2-by-2 in the mornings and closes them at night.