Garden Frames: The Cold Frame
A useful cold frame for the small home garden is one with a sash of six by four feet. If a two-light frame can be used, far more can be done in the way of raisingand sheltering winter plants. The frame should usually be about in. deep at the back and sloping down for 4 or 5 in. to the front.
In association with the frame a hotbed can be built up to make it possible to raise seedlings requiring heat in the early part of the year. It should be remembered, however, first that a hotbed needs fresh stable manure and continual stores of supply so that the heat can be maintained, and also that plants raised in a hotbed will be tender and will need hardening before they can be planted in the open garden.
If only one frame is available, therefore, it should be treated as a cold frame and not as a hotbed. To make a hotbed, fresh stable manure with strawy litter and leaves are stacked together and turned at intervals of two days while the manure is very hot. After a week or ten days the manure should be ready for use and should be built up into a bed 3-4 ft. deep, and wider and longer than the size of the frame, so that there is an 18-in. width round the outside of the frame. After this the frame is set in position. When the temperature has dropped to about 75°,is filled in, about 5 or 6 in. deep, all over the bottom of the frame.
Seeds should not be sown immediately in this soil while the temperature is still high. The usual practice is to use seed boxes filled with ordinaryand to stand them in the frame, raised on bricks, so that air circulates all round them. By the time the seedlings in these boxes have germinated, the temperature of the hotbed will have declined sufficiently to allow the seedlings to be pricked out direct in the soil of the bed. When the temperature of the inside of the frame drops, more fresh stable manure must be piled round the sides, and renewed from time to time in order to keep a fairly even, warm temperature round the seedlings.
Of the plants that can be grown in frames there are a good number suitable for indoor decoration as well as plants raised for kitchen use. They are, of course, the half-hardy—which are sown in the frame in the early part of the year, and after hardening oft are transplanted to the open garden— and these include such things as Stocks, Asters and Zinnias.
The frame is also used for bulbs during the early stages, the bulbs being brought later into the warm greenhouse or to the living-room.. The frame can, however, also be used for plants of, , , , , and such bedding plants as Calceolarias, Geraniums, Carnations, and so on.
Frame culture is also a useful way of growing tomatoes,and other slightly tender kitchen crops in cold, exposed gardens. When tomatoes and cucumbers are grown, bamboo canes are usually placed horizontally across the top and the plants tied to these as if they were ordinary sticks. The frame lights are removed during the hot summer. These are of course very useful in the early stages of the plant’s life.