a Cold Frame

Building/Using a Cold Frame

Chris Dawson explains how to use a cold frame for vegetable gardens.

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Look at these wonderful vegetables. Pick fresh, ready to eat, right out of the garden. Vegetables like these, always seem to taste better when you grow them yourself. Today I'm gonna show you how to get a jumpstart on your vegetable garden by using a cold frame. Here's one Better Homes and Gardens design for a cold frame project that you can do. Today, I'll just take you briefly through the making of this cold frame so we can get to my favorite part - the gardening. For detailed instructions on how to build this cold frame and other garden projects, visit us on the Worldwide Web at I'll begin by cutting the base pieces to blue print specifications. Since the base will be mostly below ground, using Redwood, Cedar or pressure-treated wood is best. I'm using Redwood. The Redwood lid supports are great feature of this cold frame. So these are what I'm drilling and cutting now. For the above ground portion of the cold frame, I'll cut the back and sides from the standard 48 by 96 inch piece of plywood. A second cut to each side is necessary to create an arch for the plexiglass roof. So I've measured and marked the radius of the arch according to the blue prints. This is what I'm cutting now. To cut the 1/8 inch plexiglass roof, I'm using a 10-inch table saw with a carbide steel blade. And the next two pieces I'll cut will work together to support and secure the plexiglass roof at the back of the cold frame. The first piece will provide a support surface for the roof. The second piece, the piece I'm cutting now, will be anchored atop the roof to secure it. This rabbit cut will accommodate the 8-inch plexiglass and offer even support to the roof as it arches to meet the face. For the face of the above ground portion, I'll make 2 cuts to a pine 1 by 4. I'll make the first cut to match the width of the cold frame. Then, I'll bevel it to accommodate the angle at which the arched plexiglass roof will meet and be anchored to the face. For additional support, I've also attached to the face, a one by two with a beveled edge. I'll use screws to anchor the roof to the arched sides. Now that the cold frame has been assembled, I'm going to add a couple of finishing touches and find a place for it in the southern part of the garden. Early spring with the weather transitioning out of the cold and gray of winter can be a tricky time to put your small vegetables and seedlings outdoors. But that's where a cold frame like this one comes in. It looks a lot like a greenhouse. I'll place this one in the southernmost part of the garden here where it gets about 6 to 7 hours of sun and day. And we're gonna use that sun's warmth for the solar energy to our advantage to get our seedlings off to a good start. The first thing you do to install your cold frame is dig a trench. I'm going to place mine about 2 inches into the soil. You wanna back fill along the edges to anchor it in place. This will seal the cold frame and keep air leaks out. This design has lid-supports on the side, which we use to prop open the lid. Make sure you don't cover these with soil. I pre-cut my foil-faced aluminum insulation and we'll set it in on all four sides. The foil should face the inside. This is in essence our heat-retaining source. Now, I'm ready to backfill the inside. Make sure that you have at least 2 inches of soil along all sides. Again, this seals it and keeps the cold air out. Now, the only thing left to do is to place these young vegetables and I wanna get [unk] start on into the cold frame. Some of the ones I've chosen are some lettuces, cabbage, Swish chard, some celery, tomatoes and color greens. Cold frames are excellent for hardening off or acclimating seedlings you started inside or that were grown in the green house, transitioning them to the great outdoors. The cold frame is very versatile. It can be used to start seeds, to climatize young plants, and to protect plants that are too tender to be planted in open ground. Your cold frame can also become a salad in a box. You can grown greens in it. Sometimes, almost year-round. Bulbs that need a shell-period to bloom like these tulips can be wintered over in a cold frame in some parts of the country. With the plants inside and colder weather close the lid to retain the heat, but you'll notice that the lid is adjustable and it can be propped open when needed to provide ventilation. Think of your cold frame as a safe place to strengthen and protect your plants practically year-round. As I'm done here, you can get your vegetables ready for the garden and enjoy them a lot sooner with the help of the cold frame.