ii6 
VEGETABLE GARDENING 
cold frames are placed on top of the ground, the sides do 
not need to be so high as for hotbeds, unless the hotbed 
frame is simply placed on top of the manure, in which 
case there would be no difference in this respect. The 
height of the sides, or, in other words, the depth of the 
frame, must be determined by the size of the plants to be 
grown. It takes a deeper frame to grow tomato plants 
than to mature a crop of forcing radishes. Ordinarily, 
FIG. 24. PERMANENT COLD FRAMES 
a 12-inch board or plank is high enough for the north 
side and a 6-inch piece for the south side. An additional 
depth of 2 to 4 inches is an advantage in some lines of 
work. If flats or plant boxes are to be used in growing 
cabbage and tomato plants, the frame at the north side 
should be 16 inches deep and at the south side 10 inches. 
The frames may be movable or stationary. The most 
common plan is to nail the side boards, which should be not 
less than 1 % inches thick, to stakes placed on the outside. 
Chestnut lumber, 1^2-inch thick, makes very satisfac- 
