
A cold frame is a most useful structure to add to a home garden. It can be used for plant storage, early and late sowings of food crops, for the protection of hardy vegetables over winter, and for plant roots which cannot stand wet conditions while dormant. Construction can be as simple or elaborate as the gardener cares to make it.
Such a structure is essential to the successful operation of an amateur's greenhouse, providing extra space and ideal conditions for hardening small plants before transplanting to the open garden, for rooting cuttings, for germinating seeds in summer and protecting small plants over winter. And every home gardener will find a dozen other uses suited to particular types of gardening.
A cold frame need not be elaborate to be useful. To prove this statement we should consider its basic purpose.
It could be defined as a structure designed to create an artificial environment for the growing of plants by providing some measure of protection from the atmospheric conditions considered adverse to plant growth. Thus, any structure providing the necessary environment and protection could be classed as a cold frame.
This means that a planter on a balcony or a window box, half filled with compost and covered with one or more pieces of glass constitutes a cold frame. A packing case or large box, 12 in/30 cm deep, also forms a frame, as does a hollow in the centre of a compost heap with the sides left to support a glass cover.