You can add from 10F to 15F of warmth to your fall and winter garden by taking advantage of windbreaks and walls. Many gardeners have discovered by surprise that a south-facing wall of the home, shed, or greenhouse is ideally situated for constructing easily built structures that use the free solar energy of the sun.

Cloches

Cloches provide an elevated warm climate around your winter row crops. They can best be described as portable green houses of various designs that work with solar energy to warm the immediate row or plant they are placed over. Many designs have been tried. Ideas range from very stiff wire frames holding glass panes, to clear two-liter plastic pop bottles with their bottoms removed.

All cloches have two drawbacks to consider. First, on bright sunny winter days they have to be manually ventilated, to prevent excessive heat build up. Second, poorly constructed cloches can become kites during winter windstorms.

Cold Frames

Cold frames are permanent structures that considerably lengthen the growing season. They are an excellent way to grow fall and winter crops. Cold frames provide protection from strong winds, elevate the daily and nighttime temperatures around the plants, and protect frost sensitive vegetables or flowers. They are easy to build and the vegetables and flowers in them will require minimal care. In short season areas, a cold frame will allow you to start seed up to 8 weeks earlier than you can outdoors.

You can use an old window sash of any dimension to build a cold frame. Fiberglass or polyethylene can be used if the glass is broken. The ideal cold frame is built about 18 inches at the back and 12 inches at the front. The slope allows rain to run off and affords a better angle for gathering the sun's heat.

Your cold frame should face south for maximum exposure to sunlight. Also select a location with a slight ground slope to provide adequate drainage away from the frame. To provide ventilation, partially open your cold frame during sunny, warm weather. During cold snaps, cover the cold frame with burlap or heavy cloth to provide extra warmth.

Hot Beds are cold frames with a source of bottom heat. Today, that heat comes from electric heating cables. A few hot beds are still constructed using the old method of a layer about a foot and a half thick of decomposing manure beneath the soil of the cold frame as the source of heat. Either way the hot bed remains frost-free during the winter.

Greenhouses

Greenhouses are structures that provide frost-free climates all year around. There are perhaps as many designs for greenhouses as there have been imaginative gardeners. Unheated greenhouses are great for raising seedling crops of many of the most delicious leafy and root vegetables. Greenhouses can also be heated for raising tropical plants. Some greenhouses as far north as Alaska have been used for extensive winter production of commercial crops like tomatoes and cucumbers!