A cold frame can protect your herbs and significantly extend your gardening season. It is very useful if you want to have a longer gardening season or you live in a cold place.
Another beauty of a code frame is that is very straightforward to build. You basically make a wooden transparent open-top box to cover your herbs. It would be great if you have an old door or window to be salvaged into a cold frame.
Keep reading detailed building plan here and watch the video for more tips.