CONSTRUCTION OF GREENHOUSES 



171. Extent used. Greenhouses are in far more gen- 

 eral use among market gardeners than they were 10 or 

 15 years ago. They have become especially numerous 

 near railroad lines affording satisfactory shipping facili- 

 ties and large cities providing good markets for forced 

 vegetables. When a grower learns that a greenhouse 

 is a profitable investment the usual tendency is gradually 

 to increase the area of glass, as many examples of such 

 expansions will prove. The first house is perhaps very 

 small and built for the purpose of starting early vege- 

 table plants, for which it is found convenient and satis- 

 factory ; but the owner is often unwilling to have it idle 

 more than half the year, and, therefore, he tries a forcing 

 crop. If his efforts in the production of crops under glass 

 prove successful, the greenhouse area is increased and 

 new houses are built from year to year, until the grower 

 is known as a vegetable forcer rather than a market 

 gardener. The greenhouses furnish better conditions for 

 starting early plants and they may be used 10 or n 

 months in the year if the establishment is properly 

 handled. It is not uncommon for market gardeners to 

 operate an acre or two of greenhouse space, while a much 

 larger proportion of growers have from 1,000 to 10,000 

 square feet of glass. 



172. Advantages. If forced vegetables can be made 

 profitable in connection with market gardening, there 

 should be no hesitation in constructing greenhouses. 

 They enable the grower to keep in touch with the market 

 the year round, and they provide employment in the win- 

 ter when it is often difficult to find sufficient work to 



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