Building a Cold Frame: No Need to Buy Any Costly Kits
While there are many commercial cold frame kits available in the market, individuals serious about having fresh vegetables in their backyard prefer to build their own cold frame. Building a cold frame can be easy, but you should know the right materials to build one, its correct positioning and size. Framed glass is generally used for the covers or roof. However, you can use acrylic instead of glass. Modern cold frame roofs are made from double glazed polycarbonate frame, which a safe alternative option to glass as polycarbonate does not break or shatter.
Wood might be the best material for the sides of the frame, but make sure that it bears dampness. You can paint the wooden surface to protect it from moistness. Most people use redwood or cedar that does not get damp. After building the frame, add well-composted soil at least 16" deep. Make sure your cold frame is ventilated because when the outside temperature is below freezing point, the frame can become too hot inside. Proper ventilation would allow the hot air to escape. Make sure your cover has sliding panels to ensure proper ventilation. During cold weather, please close the cover at night if the temperature is below freezing.
Building a cold frame is very easy if the above guidelines are followed. You can then grow crops such as spinach, onions, carrots, leaf lettuce, chard, radish etc.