“The Market Gardener” by French artist Robert Antoine Pinchon depicts an autumn garden in the city of Paris circa 1850. Within the city limits, at a more northern latitude than the Canada-US border, and without the use of machines, electricity, artificial heating or artificial fertilizers, Parisians once grew enough food to satisfy the needs of their entire city, even through the winter. In his painting, Pinchon illustrates a method of season-extension in which eighteen-inch diameter glass bell jars (or “cloches”) are placed over the crops, creating miniature greenhouses.
The autumn scene Pinchon paints is so alien to our modern food system, it looks nearly futuristic. And it should be... these French bell jars amplified sunlight, prevented heat loss, and shielded plants from harsh winds, extending harvest far into the winter months. Loads of decomposing manure (always surplus in horse-drawn Paris) helped create a “hotbed” from beneath. The bell jars were covered with blankets or straw on cold nights and propped up for ventilation during the day.
In the 1970s, farmer Eliot Coleman resurrected this French system of low-energy winter harvest on his Maine farm. He now sells the majority of his crops from September to May, referring to August as his “second spring.” Instead of the bell jars, he uses a system of unheated greenhouses and low tunnels—like miniature hoop houses the width of a single garden bed. His plastic insulation passively captures daylight and radiates heat to the plants, each layer moving his garden one and a half growing zones south, or about 500 miles.
Coleman writes, "We [are] not doing battle with the cold of winter, as one thinks of doing in a heated greenhouse while trying to grow hot-weather crops, but rather we [are] creating a simple protected microclimate, sufficient for the needs of our hardy plants. It is like the difference between sitting inside by the fire on a cold day or being outside with enough layers of clothes on to keep you comfortable. Second, we... pay attention to the fact that once past the middle of November most of the crops were not growing much anymore. They [are] just sort of hibernating and waiting for us to come and harvest them. In other words, we [are] not actually extending the growing season as you would with a heated greenhouse, we [are] extending the harvest season (from The Winter Harvest Handbook)."
Coleman's Winter Harvest Handbook has become an important resource for small-scale organic growers in the northern US, helping “reconnect [us] to the grand design of the earth.” In it, he explains how to harvest fresh, sweet, and green winter crops without the use of fluorescent lights or artificial heat.
In his unheated greenhouses, Coleman can grow a variety of vegetables all winter long—things like spinach, scallions, carrots, leeks, baby lettuces, and watercress. He even manages to harvest a crop of tender potatoes in early May. These winter crops take longer from sow to harvest, but they do not suffer the stress of heat, pests, and weeds like summer crops do. They are also sweeter, because of the increased sugar concentrations plants use as "antifreeze."
Here in the north, farmers and markets deal with an overwhelming abundance of both work and produce in the summer and resign to eating far-off produce and finding off-farm employment through the winter. The warming power of manure has been forgotten, along with the hardiness of young greens to spring back after frost and the ability of snow-cover to insulate the earth from freezing. The production value of our local soils has been ignored, not to mention the utility of our root cellars, which have great capacity to sustain life.
As we learn to accept the ebbing, flowing patterns of the earth, we discover that winter is not a bleak lesson on abstinence or food miles, but rather, of candy-sweet carrots hibernating under glowing glass orbs and billowing plastic tunnels. The simple success of a winter carrot is a sign that moving into the future is simple--a matter of reaping an agricultural heritage already sown and tapping into natural cycles, ancient and hospitable.
"Robert Antoine Pinchon, 1921, Le Jardin maraicher, oil on canvas, 74 x 100 cm, Musée des Beaux-Arts de Rouen." by Robert Antoine Pinchon - Histoire des Arts. Licensed under Public Domain via The Commons.