Every spring and fall I try to make it out to the Chicago Botanic Garden to see what inspiration they might toss at me in those transitional gardening seasons. In both the fall and spring I am completely and totally captivated by the Chicago Botanic Garden’s lovely row of cold frames in the vegetable garden. Cold frames are used as a tool to protect your plants from frost either in spring or fall and can be an invaluable tool for lengthening the gardening season, particularly in northern states. It can also be used as a protective spot in southern states for container plants and vegetables when there is a cold or frost warning out.
Chicago Botanic Garden utilizes their cold frames quite effectively. Having a cold frame up against a building like the above photo can insure more warmth is absorbed by the building wall and reflected into the frame itself. When considering a location for you cold frame, search for a south-facing, sunny location with low wind issues.
Cold frames need attention and perform best when kept cooler, rather than hot. For example, keep the temperature inside below 60°F to 65°F for cold weather plants that grow best in spring or fall, and under 75°F for other warm weather plants. Be sure to prop the lid open when needed to help regulate the temperature. Place the lid back on tightly to keep the interior warm. When below freezing temperatures hit, pile extra insulation such as blankets, newspapers, or straw on top of the glass. Snow is quite heavy and can sometimes break glass, so no matter when you are working with, it will need regular attention to optimize plant growth.
Consider purchasing or making a cold frame to extend your garden growing season. Gardening can be nearly a year round experience, even in the northern states with a little creative assistance from a cold frame. They are easy to install or make yourself from recycled products so that you can protect your plants in the garden sustainably throughout the colder seasons.