Joseph De Sciose
Imagine picking crisp, fresh vegetables from your own garden during the coldest parts of the year. When the grocery stores are offering only frozen peas, you can create a cold frame that will give you the ability to grow vegetables throughout the year. Cold frames are easy to build and cost only about 20 bucks. They are also a great way to start vegetables outdoors in the spring a few weeks earlier than you normally could.
How It Works
Cold frames are basically miniature greenhouses. They trap the sun's heat throughout the day and then slowly release it during the night. This gives up to a 10-degree boost in temperature for young seedlings. For instance, if the temperature goes down to 25 degrees (a killing frost for most plants), a cold frame will keep the minimum temperature at around 35 (warm enough for your cool-weather vegetables to survive).
To increase the effectiveness of a cold frame, position it in a sunny, south-facing location. This allows the maximum amount of light to reach plants throughout the day. Also, consider putting the frame next to a wall or hedgerow to give plants added protection from cold winter winds.