When Wayne Burleson's wife Connie said no to the construction
of a vegetable cold frame in her flower garden, he decided to build
one on wheels. By the time he was done, he had a unit with
in-floor heat, a thermostat, and automatic venting. Instead of just a cold frame, he realized he now had a winter garden. "It's a little pricy, but you can't compare the taste and quality with what you buy in the store," says Burleson. "At 5,000 ft. elevation, we have 90 days to get our vegetables ripe. With this setup, I can ripen peppers and other plants we could never grow outside."

His mobile cold frame is a 2 by 4-ft. wooden box with 2 in. of insulation on the bottom and sides. The sides slope from about 3 ft. at the back to 2 ft. at the front. The slope ensures that all the plants get adequate light.

"I put a layer of sand in the bottom with a soil heater cable in it and a couple more inches of sand over it. I then filled the rest of the planting space in the box with a mixture containing equal measures of each compost, vermiculite and peat moss," he says. "The thermostat keeps it at 76 degrees."

A set of rubber-tired wheels lets Burleson move it as needed. The top is a salvaged thermopane window. Realizing that when the sun came out, anything under the glass would fry, Burleson installed a greenhouse vent arm. It raises the window/roof when the air inside the box gets too warm. As it cools, the window is lowered back into place.

"The minute I turn on the grow light, everything grows like the dickens, "says Burleson.