Cold frames can be used to extend the growing season for many food and ornamental crops, primarily by providing increased warmth in early spring. This means that it's possible to harvest vegetable crops ahead of their normal season when they are extremely expensive to buy. Some crops suitable for growing in a cold frame include lettuces, parsley, salad onions, spinach, radishes and turnips etc. One vegetable crop can occupy the whole of a cold frame or a combination of crops can be grown so that they mature in rotation in order to get a wide range of different vegetables throughout the year from a single cold frame.
