CHAPTER VII 

 THE TEMPERATURE FACTOR * 



The vegetables grown in our gardens are native to many differ- 

 ent countries, differing widely in climatic conditions. Each kind 

 of vegetable has its own peculiarities and thrives best under cer- 

 tain climatic conditions. When an attempt is made to grow 

 many sorts in the same garden under the same conditions, it is 

 not surprising that some thrive better than others. However, 

 many of the difficulties encountered can be overcome by adjusting 

 the time of planting each crop to meet its temperature and mois- 

 ture requirements as fully as possible. Failures in gardening 

 often result from planting some crops too early and others too 

 late. Each should be planted at the season most favorable to its 

 development. 



Vegetables are usually classified as ''hardy" and "tender." 

 This classification is based upon the fact that certain vegetables 

 will endure the ordinary frosts of spring without injury, while 

 others would be killed if subjected to the same temperatures. 

 This classification implies that danger of frost injury is the chief 

 distinction between the two classes of vegetables, and that while 

 the ''hardy" vegetables can safely be planted "before danger of 

 frost is over," there would be no objection to planting them after 

 that time. As a matter of fact many of the so-called hardy vege- 

 tables would be as utterly ruined by the heat and drought of 

 summer as are the tender vegetables by the light frosts of spring. 

 They demand cool weather, and without it will not produce an 

 edible product. Furthermore, the danger of frost injury is. not 

 the only reason the so-called tender vegetables should not be 

 planted early. The cool weather normal to that season of the 

 year, though no killing frost occurred, would preclude the proper 

 growth and development of the crops in question, for they 

 thrive only in warm weather. A more satisfactory wording for 

 this classification of crops would therefore be "cool season" and 

 "warm season" crops, for these terms suggest the conditions 



* This chapter is essentially the same as an article written by the author 

 for the Illinois Agriculturist, February, 1911, and later published in Circular 

 154 of the Illinois Agricultural Experiment Station. 



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