Early season gardening - cold frame

Gardeners all, whether your garden is big or small or even lacking, everyone has room for a cold frame.  Nothing extends your gardening season more than a cold frame.  TPP likes these small cold frames because they can be easily moved, easily sited in a sunny location.  It works well to use a potting soil mix in planting boxes because they warm up faster than the soil beneath.  Here's a cold frame with bibb lettuce just a week after the seedlings were planted, and the nights have been freezing, but the days just above freezing.  The other inhabitants are some parsley, both curly and flat, and some mesclun mix.  With a cold frame you'll be harvesting salad before your regular garden hardly gets going.  This cold frame is sited on top of a sunny herb garden, and it will be gone before it's time to plant real warm weather herbs like basil, so now you get another crop from this space.  But why stop there?  Use your patio or the edge of your driveway or a porch roof (if you can reach the cold frame out of a window.  Almost everyone has room for this type of gardening.  Still make certain that you only grow cool weather crops: lettuce, spinach, mesclun, green onions, baby bok choi.