In this article I will give you some ideas about how to build a cold frame. A cold frame is used to get an early start on your garden plants, usually tomatoes, peppers, and other plants that are sensitive to cold weather and frost. A cold frame (also called a hot bed) has the benefit of providing warmer soil as well as protection from cold and frost. This will encourage your seedlings to grow more rapidly. It also allows you more control of pests and the feeding of your seedlings.
You can build a cold frame for almost nothing but a little effort using used or gleaned materials that have been discarded or sold cheaply at yard sales, auctions, and flea markets. Used windows in frames and glass doors can be used to build a cold frame that can be used for many seasons. Fasten them together to form a box like structure in a place that gets direct sunlight all day and you are in business.
You can make a cold frame from PVC pipe bent into hoops or fitted together with fittings to form a frame with cheap plastic sheeting stretched over it. The plastic sheeting will have to be replaced every year but it can be purchased cheaply at any hardware store. This works as well as any other cold frame. It is just less convenient.
You can use any old wooden packing crate or box with a window covering it or an old refrigerator or freezer with the door removed works well also.
There are some things you can do to help control the temperature in your cold frame. You can add several rocks inside to absorb the suns heat during the day and radiate it back out at night. You can also cover the top with an old blanket or other cover to keep the heat in at night. One trick I use is to put a 4 inch layer of manure in the bottom under my soil. The manure gives off heat as it decomposes and warms your cold frame in the process.
Now that you know how to build a cold frame, there is nothing to stop you from getting a head start on the growing season. When your neighbor notices you have ripe tomatoes several weeks before everybody else, you can brag about your cold frame that you built yourself. Cold frames can also be used in the Fall to extend your growing season the same way they are used in the Spring to get an early start.
If you just do not have the time to build your own, or you had rather buy well designed, reasonably priced cold frames, you can find some nice ones here ; cold frames