Glasshouses vs. Frames 45 



but they do not grow. There are two general types 

 of the forcing* of plants : they may be started under 

 glass, and then transplanted into the open ; they may 

 be grown to maturity under glass. 



1. QUANTITY AND COST OF GLASS REQUIRED 



How much glass the vegetable - gardener needs de- 

 pends (1) on how intensified his operations are, (2) in 

 what season he wants the major part of his crops, 

 (3) the region in which he is, (4) the kinds of crops 

 he grows. These factors are largely determined, in 

 their turn, by the man's location with reference to 

 market, and the price of labor and land. Very small 

 areas sometimes have sufficient glass to cover them. 



Glasshouses are increasing in number and popu- 

 larity. They are driving out hotbeds for the forcing 

 of winter stuff. But for general vegetable -gardening, 

 the coldframe and hotbed will remain, although their 

 relative importance is likely to diminish. These humble 

 structures are desirable because they are cheap, because 

 they allow the person quickly to change or modify his 

 business (a great advantage on rented land), and 

 because they can be removed when the spring forcing 



*The author should say that the word forcing is used in many senses. He 

 uses it as a generic term to express the idea of making plants grow and bear 

 at other times than their usual or wonted season in the given place or 

 locality. Most greenhouse plants are not forced : they grow and bear in their 

 normal season, and we afford them the climate to enable them to do so. Thus 

 begonias are not forced, merely because they bloom in March : carnations and 

 tomatoes are. The term forcing is often used in a very special sense by 

 florists to designate the rapid driving -out of bloom from bulbs and tubers, 

 as with lilies-of-the-valley and tulips, 



