Basically most cloches are two sheets of glass resting at an angle to each other and supported by wire. They can be moved about the garden to give protection and warmth toor as and where required. More of these glasses can be added to give a continuous run. A variation is achieved by 4 sheets of glass -to one cloche, 2 upright and 2 forming a top arch; these are aptly called barn cloches. It will be realised that each end is open, and while cold conditions rule a piece of glass or card can be placed so as to keep the interior cosy, but it must be moved for airing, as damp is far more fatal to and young growing plants than is dry cold, even a slight degree of frost. In particular this applies to vegetables and salad produce. It will be noticed that the ground inside the cloches seldom becomes frozen. If they are set dead level full protection from cold, drying winds is afforded and if set at right angles to the prevailing wind they should act as windbreaks to other crops near by. Always place in a sunny . Cloches also protect from bird damage and heavy rains — in very wet districts like the west coast of Scotland and the Lake District can easily rot in the ground. Earlier sowings under cloches give the plants a flying start and hasten maturity. Vegetable seeds can often be sown a month earlier. This factor is of tremendous importance to northern gardeners who are usually faced with a shorter growing season than those living in the sunnier south. To raise the soil temperature, thereby hastening germination of seeds, cover the vegetable rows with the cloches 10 days before the actual sowings.
Under cloches tomatoes can be planted out 6 weeks earlier than usual, avoiding damage from late spring frosts.
Carrots can be sown in January and pulled in April, or in August for eating in November and December. July or August-sown lettuces can be cut in November. Varieties of peas like Meteor and Kelvedon Wonder may be sown in November for picking in early May. Lettuce or radishes may be sown on both sides of the peas to gather before the peas mature. Forflower seeds, cloches are invaluable, as they give just enough protection for germination and growth without setbacks. Sweet peas can be sown in early autumn under cloches, ensuring a better developed system and earlier cropping with no check to growth. A leading maker of cloches has issued the following useful table showing when certain vegetables, etc., are best protected by cloches.