Hot Beds & Cold Frames

Crops require shelter from cold temperatures (and the wind) to different extents. This can be done with different means, from simple to complex. Systems can have more than one layer of protection, and some can generate their own heat. To protect crops, you might use the following.

• straw or (chopped) leaf mulch to cover, with or without bales as sides

• old blankets or bed sheets to cover, held up with stakes

• old windows to cover, letting in light to heat up the area on sunny days and held up with bales (i.e., a simply constructed cold frame)

• a hoop system with row cover

• a low tunnel constructed of hoops and plastic sheeting, with or without frost blankets

• a cold frame constructed of wood

• an unheated greenhouse

• a hot bed — a growing frame warmed by heat generated from decomposing organic matter, ranging from animal bedding/manure, leaves and forest waste to wool, seaweed and cotton clothing

• a low tunnel, cold frame or hot bed inside a greenhouse

Note: Any system that generates heat from decomposition or the sun will have to be monitored for overheating as well as for maintaining a sufficiently warm temperature.