A cloche can protect plants from wind, hail, frost

May 9, 2012
A clock in the garden won’t protect much, but a cloche certainly can.  Simply put, a cloche is a large bell-shaped glass that you put over tender plants to protect them from wind, hail and frost.

For spring gardens, the clock is running.  A clock without bells, of course, would not really be a clock, because clock comes from a word meaning bell or bell-shaped, and only timepieces with bells were first called clocks. As usual, the French have a word for it: cloche, meaning bell-shaped.

A clock in the garden won’t protect much, but a cloche certainly can.  Simply put, a cloche is a large bell-shaped glass that you put over tender plants to protect them from wind, hail and frost.  Not only are cloches functional, they add a bit of charm to the gardenscape.  Cloches have done double duty of everything from keeping cakes fresh to sheltering small heirlooms.

Even if a frost or hail does not kill a plant, it can damage it so completely that the plant will not produce well.  Broad-leaf crops such as lettuce that have their growing point at the top of the plant are more open to frost damage than grass crops such as corn.

Most beans are sensitive to frost. Some beans sprout leaves again after a light frost, but usually they are from axillary buds in the leaf axil. One of these branches will then become the main axis of the plant if the first growing point is killed.

Some crops such as corn plants less than six to eight inches tall (five-leaf stage or less) will recover from frost because at that size, the growing tip is still below the soil surface and undamaged.   This is why spring frosts rarely kill corn.

Other plants such as beans may recover from a frost if their growing tip is damaged.  A side shoot might take over and become the leader or new growing tip.  Other more tender plants will die completely when the growing tip is damaged.

Since cloches act as mini greenhouses, holding in humidity given off by plants, as well as protecting them from drafts and wide swings in temperatures, they are ideal for houseplants such as maidenhair fern, gloxinia, rex begonia, African violet, polka dot plant, and Venus fly trap.

Outdoors cloches can take the form of row covers and hoop houses.  Commercially available row cover is often clear plastic or spun bonded polyester. You can lightly drape the covers over the growing plants to protect them or you can put wire hoops in place and drape the fabric over the frames forming a low tunnel.

Most gardeners leave the row covers in place for several weeks until the crops are well established and danger of frosts has passed.   A garden cloche is open on the bottom and sits directly on the soil, so plants can be started directly outdoors earlier.  For potted plants and seed flats, a cloche can increase the humidity and temperature, and speed up how soon they can be set out in the garden.

Not only does a cloche act like a mini greenhouse, it protects from insects, wind and weather.  Because a cloche is movable, you can reuse it throughout the season as your plantings advance. This cloche is also a good size for a small salad garden.

However, it is the individual cloche, or bell jar, placed over individual plants that adds that certain French country look to the garden.

You can buy pricey glass cloches from nurseries or specialty mail-order houses, or you can make somewhat less attractive yet more practical ones.  Use a serrated knife to cut the bottom out of plastic milk jugs or soda bottles.  Remove the cap so that heat does not build up to lethal levels and press the open end down into the soil and voila, you have a cloche.  You can also plant a seed and place a cloche over the individual seeds.

Too much of a good thing is “je ne sais quois,” definitely not a good thing. On hot days, be sure to lift the cloche or pull back the row covers so you do not burn your plants.

Generally, you don’ need a cloche over woody or hardy plants. You can also use a cloche to help with a process called hardening off, the gradual process of strengthening delicate seedlings to withstand the severe weather outdoors.

So with weather up in the air, so to speak, early crops can be protected by a spun fiber cloth row cover or individual cloches.  You will save many a plant from early death and the ones that do die, well, as we say, “c'est la vie."

  • Paul Barbano writes about gardening from his home in Rehoboth Beach. Contact him by writing to P. O. Box 213, Lewes, DE 19958.