It is getting late enough in the season that we might be able to squeak by without having to use more frost covers. For those of you that don't have a frost cover system, you can use milk jugs, buckets or plastic bottles for a temporary system if the need arises. It probably works best if it is only a quick cold spell and is going to be a light frost.
Denise tried it a few years ago but prefers using the frost blankets. But then again, she is covering lots of plants so that makes sense. She does have a friend that uses milk jugs but the thing you have to watch out for is over heating. You don't want to broil the plants you just saved from freezing so you will need to go out early and move the jugs or figure out a way to vent them easily.
My research on the web shows a multitude of ways to do it. Here is one link to a how to -
Milk jug as cloche. I was curious how well it would fit over Mark's tomato plants so I took my sample up to the garden to give it a try. It went over some of his tomato plants but not all of them.
Leaving the bottom attached really does make it easy to anchor down with a rock or any other heavy object.. But you do want to pull dirt up around the edges so no cold air gets in under the bottom. Letting cold air in is going to counteract the effort to capture the radiant energy coming up from the ground.