Cloches are portable forms of protection, rather like miniature
cold frames. They are mainly employed during the winter and early spring, but they can be used at any time of year to bring on a crop
or to protect it.
There are frequently times when you want to cosset a few plants. They may need protection from the cold or it may be that they are not particularly worried by the cold but need a little warmth to make them grow faster. One row of strawberries, for example, can be covered with cloches to make them fruit one or even two weeks earlier than they would if uncovered. During the winter, broad (fava) beans will come on better if they are protected not only from the cold but also the extremes of rain and wind. Cloches can also be used to protect plants from predators.
In wet and cold areas cloches can be used to cover the ground so that it both dries out and warms up ready for sowing. This will often enable the gardener to sow several weeks earlier than the weather would otherwise allow in the unprotected garden.
In autumn, cloches can be used to cover ripening or harvested vegetables. For example, cordon tomatoes can be lowered to the ground onto straw and allowed to ripen under cloches, while onions that have been harvested in a wet summer can be placed under cloches to “harden off” before storing.
Some of the earliest cloches were glass bell jars – like upside-down glass vases – which were placed over individual plants. Other traditional cloches were made from sheets of glass, and the earliest types were held in iron frameworks, and resembled miniature greenhouses. Later, cloches became simpler, and the glass was held together by metal or, more recently, plastic or rubber clips. These were known as barn or tent cloches because of their shapes, and could cover a single plant or a whole row when arranged in a line.
Glass is still used, but most cloches are made of polythene (sheet vinyl or plastic) or rigid plastic. There are two main types. One is made up of individual units, which link up in some way, and the other is like a miniature polytunnel, with a single sheet of polythene stretched along the length of the row.
All cloches will do the job they are designed to do. Glass should last the longest, unless you are careless. Although plastics and polythene (sheet vinyl) have a more limited lifespan, they are generally cheaper to replace and are usually lighter and easier to store.
Making your own
Bought cloches may not fit the length or width of the rows in your garden, especially if you are growing in deep beds or blocks. It is relatively simple to make your own. For smaller rows, several hoops of galvanized wire are pushed into the earth at intervals of 60cm/24in and a sheet of polythene (plastic) is laid over them. Place more wire hoops over the first, so that the polythene is trapped between them and held securely. For real security the sides and the two ends of the polythene can be buried in the earth.
For larger beds hoops can be made from lengths of plastic water pipe. Place a stick or iron stake in the ground on each side of the block or row and place the end of the pipe over the stake, forming a hoop. Proceed as before, using more hoops to hold the polythene
(plastic) in place, or use strings stretched over the polythene next to the hoops and attached to wire hooks sunk into the ground.