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AGRONOMY 



This is the exact opposite of forcing. All the early spring flow- 

 ering plants may be treated in this way, being placed in cold 

 storage until required for blooming. Plants that have started 

 into growth may be retarded to a certain extent by keeping 

 the temperature lower than that required for vigorous growth. 

 Greenhouses and hothouses. Strictly speaking, a greenhouse 

 is a building used for keeping plants green through the winter, 



Photograph by Lord & Burnham, New York 



FIG. 111. A glass bouse in which a variety of vegetables and flowering plants 

 may be grown during the winter 



and may or may not be heated, depending somewhat on the 

 location, while the hothouse is a heated building in which 

 plants may be grown, or warm-climate plants protected, dur- 

 ing the winter. Ordinarily, however, this distinction is not 

 maintained and the terms are used interchangeably. A con- 

 servatory partakes more of the character of the greenhouse, 

 being properly a place for conserving and showing plants 



