When plants are put out in the garden as seedlings they are vulnerable to fluctuations in temperature especially in cooler parts of the country. They are also vulnerable to weather with damaging wind and driving rain sometimes causing them to keel over and then there are the hungry and inquisitive birds and ravenous slugs and snails. Cloches are like mini greenhouses, they allow in light, and keep in warmth and keep out the worst of the weather. Depending on which type you use they can also keep plants free from the unwanted attentions of birds and slugs and snails too.
For gardeners who want to get tender summer crops into the ground as early as possible in spring cloches are a 'must have' as they protect tender seedlings such as zucchini, tomatoes and cucumbers from irregular, early spring, weather patterns and allow them to get established whilst the weather sorts itself out and settles into reliable summer patterns.
Cloches can be large or small depending on the plant or plants they are to protect. Traditionally cloches were made from glass in the form of bell-shaped jars, these are pretty costly but they do look good. You can make your own cloches and probably the cheapest way is to use empty 2L plastic juice bottles with the bottom cut off. These recycled cloches can be placed over individual seedlings at the time of planting and then removed when foliage has started to fill them up and touch their sides. Taking the lid off prevents them from heating up too much during the day and allows for easy watering. In cooler areas, if you have the time, you can put the lids back on overnight to keep in air that has been warmed during the day.
Where you want to protect a row of plants that have either been sown or planted then a plastic tunnel cloche is most useful. These concertina out with a succession of metal hoops that can be pushed into the bed to keep the tunnel in place. If it's a windy location or just a windy time of year then you may want to place a few rocks or bricks along the bottom of the polythene sides to prevent the wind from getting under and dislodging the cloche. These polythene tunnel cloches can be bought readymade or can be made at home.
5 or 6 metres of stiff wire (no. 8 fencing wire)
approx 6 metre length of polythene sheeting around 800mm-900mm wide
2 wooden pegs about a forearm's length
A ball of garden twine
1. Cut four or five 1metre lengths of fencing wire (something about as stiff as a coat hanger) and bend each one into a hoop.
2. Push hoops into soil along row of plants - space them about a forearm's length apart.
3. Push a wooden peg about as long as your forearm into the soil about an arm's length from each of the outer hoops.
4. Cut polythene sheeting to a width of approx 800mm and the length between the two wooden pegs.
5. Tie sheeting to one end peg and run over the hoops before tieing off on the other end peg.
6. Pull sheeting down over the hoop on each side and anchor by building some soil up along its entire edge.
7. To further anchor polythene sheeting tie some string to the bottom of an end hoop on one side. Loop string over to bottom of next hoop on the opposite side and run it round bottom of hoop a couple of times before continuing to other side and repeating till you reach other end hoop.
NB. Remember that plants beneath fixed tunnel cloches will still need to be watered by hand – best to use a hose with an extendable soaker attachment for this as you can get to plants through the ends of the tunnel cloche without having to totally take it apart.