Cloches and Cold Frames
Protect crops from pests and bring on their growth in cold weather by covering them with cloches or growing them in permanent cold frames.
From: DK - Simple Steps to Success: Vegetable Gardening
Plastic Bottle Cloches
Many plants benefit from protection in cool spring and fall weather. Commercial cloches can be expensive, so large, clear plastic bottles, cut in half and placed over plants, are an effective alternative.
Usually permanent structures of brick with framed glass "lights," cold frames are useful for hardening off young plants and extending the productive season of crops such as salads and zucchini. Constructed in a sheltered, sunny spot, they are a good alternative to a greenhouse in a small garden, with the angled lights allowing water to run off and the maximum amount of light to reach the plants. A frame with a hard base is suited to acclimatizing pot-grown plants to outdoor temperatures, while a bed of improved soil allows crops to be grown in the frame. Prop the lights open during the day to provide ventilation, and keep plants inside well watered.
Corrugated Plastic Cloches
Whole rows of plants can be covered using long, low tunnel cloches, which are left open at the ends for thorough ventilation or closed off when greater protection is required. No rain will reach cloched plants, so remember to water them as necessary.
Rigid Plastic Cloches
These large cloches are ideal for protecting blocks of young plants or more substantial crops, such as zucchini or early potatoes. The warm, dry atmosphere is also perfect for drying onion crops after harvest. Anchor these light structures to the ground.