Yes, it is possible to grow winter produce around here without a greenhouse. We know because we have done it.
Our farm started out as a weekend business. In 1985 we borrowed $4,700 from Jefferson Savings & Loan and bought a used International Harvester tractor from Holmes Equipment in Elkwood. From that humble begining we started growing and selling produce, flowers and berries at the Culpeper Farmers' Market.
Terry taught vocational agriculture at Culpeper High School for 15 years. One day she decided that she would rather farm than teach, and so the farm became a full-time business for her. She greatly expanded the farm, and at one time or another she was selling at farmers' markets in Culpeper, Manassas, Fairfax, Gainesville, Fredericksburg, and Charlotteville.
Along the way, Terry began selling our greens to a business named The Fresh Link run by Mollie Visosky. Mollie was an aggregator, which means that she bought produce from local growers and delivered it to restaurants and other businesses in metropolitan Washington, DC. In late 2010 Mollie made us an unusual offer. Her customers wanted to buy local produce year-around, not just in the summer. She was looking for someone to grow local salad greens in winter, and she was ready to pay an attractive price for someone to do it.
So we started researching possibilities. Greenhouses were way too capital intensive, and we would never be able to earn an adequate return on our investment in our remaining years. But we happened to stumble across The Winter Harvest Handbook by Eliot Coleman, and that is where we found our solution. Eliot Coleman called them "quick hoops." Other people call them "low hoop houses." We call them "caterpillar tunnels" because of the way they look. But the idea is to stretch Agribon agricultural row cover fabric over PVC pipes bent into hoops.
This solution made Mollie's offer very attractive, and we came to an agreement that lasted for years. At one point we were supplying Fresh Link with 200 lbs. of greens per week. I eventually left my IT job with Bank of America and joined Terry full-time on the farm.
Winter farming is a lot of work, but it is possible. Read on if you are interested in how you do it.
Here is how we build our caterpillars. The first step is to pound 18" rebar pins into the ground to hold the hoops
Next, 1/2" PVC pipe is bent into a hoop and slipped onto the pins
The hoops need a purlin for support, which is rope looped around the center of each hoop. This prevents the Agribon from sagging between the hoops and being torn by a heavy snow
Finally, the row cover is stretched over the hoops, and clipped to the hoops.
The finished caterpillars.
One of the most phyically demanding jobs on the farm was burying the edges of the row covers in the dirt to keep the Agribon from blowing away, and then digging them up to open the tunnels. It really was a lot of work. We heard someone suggest using sandbags to weight-down the edges of the row covers. We bought some sandbags, and we were on the verge of ordering a dump truck load of sand, when it occurred to us that the one inexhaustible resource we have on this farm is rocks. So we started filling our sand bags with rocks. You could say that we were killing two proverbial birds with our very own stones. :-)
Here is a small field where we are filling the bags with rocks. When the kids were growing up, we were sure that picking up rocks would be much more fun if they had these really cool orange bags to put them in.
Here is one of the tunnels with the row cover edges weighted-down with rock bags, rather than being buried. This is much easier.
And it is much, much easier now to open up the tunnels. Just roll the rock bags away and unclip the fabric. This is a much better idea.
Our spinach growing inside a caterpillar tunnel.
Our green leaf lettuce growing inside a caterpillar tunnel.
Our red leaf lettuce growing inside a caterpillar tunnel.
Spinach being harvested from an opened tunnel.