Il8 VEGETABLE GARDENING 



care should be exercised in preparing the proper soil. 

 Unless the subsoil is brought to the surface, the land may 

 be treated as for any other intensive garden work. Fig- 

 ure 25 shows plats of frame cucumbers at Norfolk, Va., 

 with the side boards removed. The wide alleys will soon 

 be completely covered with the cucumber vines. 



168. Heating. Cold frames are sometimes piped and 

 heated with steam or hot water (162). They may then 

 be used at any season, and with their use the grower 

 can have good control of all conditions which count for 

 success. It is a recognized fact, however, that heated 

 frames are not so satisfactory as greenhouses. 



169. The use of cold frames. Cold frames are used to 

 a far greater extent than hotbeds. Plants started in the 

 greenhouse, hotbed or kitchen window are often trans- 

 planted into cold frames. This is perhaps their most 

 common use. They are also employed extensively in the 

 hardening of plants and in the forcing of fall and spring 

 crops to maturity. Lettuce and radishes are especially 

 popular for frame culture, while many other crops are 

 often grown in cold frames. Many market gardeners 

 own from 1,000 to 4,000 sash, and some growers confine 

 their operations entirely to frame culture. 



170. Forcing boxes. There are various methods of 

 making forcing boxes. The most common plan is to 

 make a frame 10 to 12 inches square and 6 inches deep, 

 and cover with a pane of glass. These frames are espe- 

 cially valuable in starting melons and other cucurbits in 

 regions where the summers are too short and cool to 

 grow a satisfactory crop without the aid of glass. The 

 frame is placed over the hill after planting seed in the 

 open, covered with glass, and ventilated when necessary. 

 Hundreds of them are used by some gardeners. 



