Winter Cold Frames

Swiss Chard grows well in a cold frame.

Ozarks Gardening

I grew up reading Organic Gardening and Mother Earth News magazines. As early as the late 1950s, my mother was composting kitchen scraps and garden debris, turning it into rich soil from the directions in Organic Gardening. I remember stories in both magazines about Helen and Scott Nearing, a couple who retired and moved to the Green Mountains of Vermont in 1932 to establish their self-sufficient farmstead. In the articles they wrote, they explained how they were able to grow vegetables the year around, even in the harsh Vermont's winters by using cold frames.

This is over a raised bed, 3 1/2 ft x 30 ft. long.

Eliot Coleman was another pioneer in the use of cold frames and wrote for the magazines I've listed. In 1968 he moved to moved to a farm in Maine, on land purchased from the Nearings. He used a simple hoop house made of bent pvc pipes, covered with 2 layers of plastic. You can see more of what Eliot promoted and his simple but effective methods here.

Over the years I have used the Nearing’s and Coleman's methods for growing winter produce by constructing simple cold frames in my own gardens. Our Ozarks climate is definitely milder than the mountains of Maine, and the methods are simple and even more productive.

The most simple cold frame I’ve used many times is a rectangle built of bales of straw. One bale laid on its side makes up one end and 3 bales laid the same way make up each side, 8 bales in all. I till up the space with a hoe, smooth the soil and plant rows of lettuce, spinach, even onion and radish seed. (Mustard greens, kale, lots of other greens grow well, too). Then I lay down a little loose straw for mulch over the seed bed and cover the cold frame bed with an old window. Some years I use a couple of layers of clear roll plastic and hold it down with scraps of wood.

On sunny, warm days I open the cold frame any time it’s above freezing. At night I pull the plastic or window cover over the top. Even in the dead of winter, when the ground is frozen and snow is piled up, I can go out to the cold frame, open it up and harvest greens and vegetables for the table. And the nice thing is, there are no bug pests in winter!

This year I’m using a somewhat different cold frame, more like Eliot Coleman's menthod. I used 8 ft. sections of 1 inch plastic pvc pipe, bent into hoops over a raised bed. The bed is 3 1/2 feet across and about 30 feet long. I braced the hoops with a single pipe at the top of the peak, held in place with duct tape, then covered the whole frame with 6 mil. clear plastic. Currently I have spinach, cilantro, 3 kinds of lettuce, carrots, onions and radishes growing. Using this method you can replant and grow vegetables all winter long, just like the Nearings did on their farmstead in Maine.

The bent-looking pipe in the foreground is intentional for the slope of the end of the cold frame.

This is a bit like Eliot Coleman's method except that I'm using a single layer of plastic rather than the double layer he used. Since I'm in the Ozarks and not in Maine, the extra insulation isn't needed. Rolled plastic has gotten somewhat expensive, too. I paid $68 for a roll of 100 x 16 ft plastic and about $2.50 each for the 8 ft lengths of 1 inch pvc pipe.

Ready made cold frame folds up and stores flat in the off-season.

Here's a read-made cold frame, above, I bought last year and have used it for 2 seasons. It's too small, but the nice thing is it easily comes apart and stores flat for the summer season. I can grow small amounts of greens without much work.

Plenty of greens, salads and onions all winter.