Hoophouses! Eat Fresh and Local Year-Round
by Jen Bush and Andrew Gaertner
When the chilly December winds start to blow and the snow starts to pile up, wouldn’t it be nice to vacation in the south of France and feast on the fresh local produce? While we all love the seasonality of Wisconsin weather, it does kind of put a damper on gardening and eating local produce when our predictable frost-free days go from May 15th to September 15th. That leaves eight whole months when we are dependent on the growers in Mexico and California to provide our fresh vegetables. It really isn’t fair. But wait. It doesn’t have to be that way. We are at the same latitude as the south of France and get the same amount of sunlight. If there was only an economical way to bring the temperature up, we could be living the good life. And there is! It is called a hoophouse, and it is a simple technology that can be part of a change in the way we think about local food, both as growers and as eaters.
Nowadays we can get all of the produce we want any time of the year. We have divorced the food from the place it came from to the extent that a bunch of kale or a bag of salad mix is thought to be the same no matter where it was grown. In every other area our culture as a whole has experienced similar separations, so that now we live our lives primarily as consumers of mass-produced, far away goods. The separation is deliberately disempowering and serves to keep people disconnected from their social and ecological communities. Growing food in a hoophouse in the off-season and buying food from local growers is a community-building act.
That the current economy favors food grown a thousand miles away should not deter us from attempting to eat locally year-round. There are several factors to successful season extension, and each one is an opportunity to think creatively. The first thing to think about is climate modification. The next is selection of vegetable varieties. And yet another is timing and succession planting.
Farmer and author Eliot Coleman is a season extension innovator in Maine. Years ago he converted from farming in the summer to farming what he calls the “back side of the calendar.” For him the winter harvest offers a competitive edge at a time when few other local growers have products to deliver to buyers. He has much experience in modifying the climate in order to extend his growing season. In his books, Four-Season Harvest and The Winter Harvest Manual, he describes in detail what has worked for him and how to try it out for yourselves. Coleman is a market grower and needs to keep his costs down in order to compete in the marketplace. He resists putting an expensive gas furnace in the hoophouse and prefers to use the heat of the sun for climate modification.
For Coleman, the art of climate modification lies in layers of protection for heat retention. The hoophouse retains the heat of the sun using the greenhouse effect, but it also protects against the cooling and drying effects of wind. Within the hoophouse, a grower can also put protective layers of row cover over the crops. Row cover is a spun poly fabric that is porous and lightweight, allowing moisture, air, and light to come through, but offering another layer of thermal protection. Even with a good handle on climate modification, season extension also depends on the correct selection of vegetable varieties.
There are many crops which are tolerant of very cold temperatures. As Eliot Coleman puts it, “So it’s cold, great! What likes cold?” We are in luck because many of our favorite crops can take a freeze. The list of hardy veggies is long and includes kale, green onions, chard, spinach, lettuce, broccoli raab, radishes, leeks, carrots, beets, arugula, turnips, bok choy, and much more. Most of these crops can actually take a hard freeze at night and recover when the heat of the sun returns. The little known truth is that most cold hardy crops actually taste better after a freeze. The cold temperature of the fall and winter promotes the development of sugars that act like anti-freeze in the plant. Without climate modification, these crops taste best in late September and October. With the help of a hoophouse, the harvest window can be extended throughout the winter. The last factors to think about are timing and succession. Although many of our favorite crops can survive the cold temperatures, the lack of sunlight during the winter means that they do not grow very much. The art of timing the harvest can be developed best through experimentation. The idea is to get a mature plant right around mid-October when the plants really slow down their growth. Start your plants too early and your crop is past, or too late and the crop is tiny. With succession planting, the grower plants several times throughout the season in order to ensure a long harvest window.
Growers can benefit enormously from the investment of time and money in climate modification. For the eater, the expanded variety of local food options gives one a greater connection to the local land and community and it offers hope for regional food security in the event that the economy changes.
You can talk to your local co-ops and grocery stores about stocking local produce year-round. Your demand can make it happen. You can also go directly to the farmer; many CSA farms offer some sort of “winter share” which combines fresh produce from a hoophouse with storage crops from the root cellar. What is required is nothing less than a profound cultural shift on the part of growers and eaters. Are you ready?
Jen and Andy have been involved in organic vegetable farming and Community Supported Agriculture for over 15 years. They currently reside in Western Wisconsin at the Lake Country Land School.