116 



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 (?-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 1^2 inches thick, to stakes placed on the outside. 

 Chestnut lumber, i^-inch thick, makes very satisfac- 



