Cold frame garden beds house a variety of fresh veggies all year
by Ian C. Hayes
The first frost touches your nose and the nostalgia for fresh tomatoes, lettuces, squash, and cabbage floods the mind. Why must it all end? Why must my beautiful garden pass into the depth of winter you ask?
The answer is that it truly does not have to end. By using simple carpentry techniques, recycled materials, and a little common sense, creating a winter garden cold frame will provide you with fresh greens throughout the seasons.
Decide what space you have to create a raised bed out of 2”x12” and 2”x8” new or reclaimed lumber—rough sawn wood from you local mill is also a good choice. Using pressure treated materials may tend to last longer but out gassing and leaching chemicals and preservatives are thought by many gardeners to taint soil quality and appear in your food.
It’s easy to find used, double-paned windows for free at the local transfer stations, or try the Hudson Valley Materials Exchange located in New Paltz. Double-paned windows provide higher insulation R-value to protect your winter crops from freezing.
After acquiring space and materials, construct your box, keeping in mind the dimensions of the windows. Create a pitch for water, ice, and snow to sheet off by using a 2”x12” as the rear of the bed and 2”x8” as the front. Depending on the width of the frame, cut the sidepieces diagonally so they slope down from the 2”x12” to the 2”x8”.
Attach the glass by pre-drilling holes and installing hinges. Be careful not to crack the glass or break the seal when drilling; this will compromise the insulation. Now that the frame is built in place and level, sheet mulch the inside with recycled cardboard or newspaper and back fill with good quality soil from the compost bin, local garden center, or nearby farmer.
The carpentry and earth moving is over, now for the fun part. Create small rows inside the frame and fill it with your favorite leafy greens. Lettuces, spinach, radish, parsley, and chards live through the winter when planted in mid fall in the cold frame. Harvest greens when they are small and there is new growth coming out. Having a supply of ready to plant seedlings under one fluorescent light indoors makes for quick replacement of eaten greens.
Make sure to vent your cold frame properly. On warm days in winter, above 40 degrees, crack the window open with something the size of a pencil. Leave it there during the day, but be sure to shut it again before dark. During the winter, moisture in the soil does not evaporate as readily due to low temperatures, so watering tends to be a non-issue. Condensation inside the frame will help keep soil moist. Frozen but hearty greens thaw quickly with daylight.
Imagine a frozen, snowy morning after a classic nor’easter in January as you sip coffee and nibble on a farm fresh omelet filled with your freshly harvested spinach. Or sit down to a salad of carrots and fresh mesclun, topped with finely sliced radishes, onion, kohlrabi and a plethora of colors and flavors, matched with your favorite red wine—all courtesy of your very own cold frame garden.
Contact your local gardener or carpenter for more information, or check out the very helpful book Four-Season Harvest by Eliot Coleman to do it yourself.