You can buy cold frames, of course, for a wide variety of prices. There are also many DIY examples out there for making your own out of an old window and straw bales, etc. This idea, however, caught my eye as being something that would be economical and practical for my first cold frame.
It is a window well cold frame. I purchased two plastic window well covers from Menards for about $5 each. Then, I asked my dad to put together the hinged frame with some leftover 2x4s and an old door hinge. We screwed the window well covers to the frame and voila! A cold frame!
The purpose of the hinge is so you can vent it. On days when the sun is shining brightly, it may actually become too hot inside the cold frame and cook your plants. Give it a crack to vent and you'll keep things just right.
We've had about three frosts since I put the cold frame over my lettuce and basil. Here is an example of what it looked like about 9 am after a frost:
This is the temp outside vs. in the cold frame:
As you can see, it's not much different. But again, it is not supposed to be a greenhouse, but rather a means of protecting from frost and giving longevity to cold weather crops, like my lettuce. FYI: the basil did not weather the frosts well, even in the cold frame, and is turning black and wilty.
Here is a peek inside:
I'll keep you posted on how long the lettuce survives! It is fun to continue to harvest salad after the frosts have begun!
