48 INTENSIVE FARMING 



cost of transportation and the factors of 

 crop insurance necessary at the South evens 

 up matters to such an extent that the forcing 

 house product can be produced at a profit. 



The list of crops commercially grown in 

 forcing houses is by no means an extended one. 

 For the most part lettuce, cucumbers, tomatoes, 

 and radishes are the crops grown and their rel- 

 ative importance is in the order in which they 

 are named. 



As a rule the vegetable forcing houses of 

 the Eastern United States are devoted to let- 

 tuce during the autumn and winter, while in the 

 spring they may be used for either cucumbers 

 or tomatoes. Radishes and beet greens are 

 often grown as catch crops with tomatoes or 

 cucumbers. 



Lettuce is the most important and at the 

 same time the most profitable crop grown by 

 gardeners under glass. The glass area de- 

 voted to vegetable forcing has for the most part 

 been erected for growing this crop. The 

 methods of handling the crop have been so sys- 

 tematized that a maximum of crop can be pro- 

 duced in a minimum of time and space. 



The seedbed occupies only a small area in 

 the nursery. The young seedlings are trans- 

 planted to occupy only about one-fourth the 



