Homemade Cold Frame

Materials

• The most important requirement for a successful cold frame is the lid. Since the intention of a cold frame is to conserve the sun's warmth, the lid must be made of glass or some other translucent material. The most common material is a window sash or glass storm door. Both are available at home improvement stores. To cut down on the expense, shop garage sales or salvage yards for used ones or check sites in your area where remodeling is in process.

  Traditionally, the frame has been made from wood but you can also use brick or concrete blocks. If you choose to use wood, make sure it has not been treated with chemicals that are harmful to plants, such as creosote, because it can leach into your vegetables. If you are concerned about how long the wood will last, choose an insect- and weather-resistant variety, such as redwood or cedar.

  Additional materials you will need are nails, hinges and latches. You will also need a hammer, measuring tape and saw. If you do not own a saw and prefer not to buy one, most home improvement stores provide two free cuts with the purchase of wood. Additional cuts are available for a small fee.

Construction

• Measure the dimensions of the window or glass door you are using for the lid because the frame will have to be built to accommodate the sash size. The frame needs to be approximately 18 to 20 inches tall so if you are using 2 by 4s, you need five for each side.

  Using 2-inch thick lumber, saw the 10 pieces to the same length as the sash. The width of the frame needs to be 1 inch wider than the sash to account for the hinge. Add the additional inch to the sash measurements and saw the 10 pieces for the sides. Nail them together to form the outside frame. You can also add 2-by-4 inch posts to the inner corners for additional support.

  Once the frame is complete, move it to the spot where you intend to plant. It is best to bury the bottom 4 to 6 inches of the frame so the wind cannot seep in between the ground and frame. When the frame is in place, attach the hinges to one side of the frame and also to the sash. Test the fit by lifting and lowering the sash and adjusting as necessary.