LIST OF FORCING CROPS. 5 



perature of 55 or below, and a day temperature of 65 to 

 70. The plants of this category are : 



Lettuce, 



Asparagus, 



Rhubarb, 



Cauliflower, 



Pea, 



Carrot, 



Beet, 



Radish, 



Cress, mustard, mints, parsley, 



Onion, 



Spinach, 



Celery, 



Pepino. 



The warm plants demand a night temperature above 55, 

 and the day temperature may run above 75 when the 

 weather is clear and bright. They are : 



Tomato, 



Eggplant, 



Pepper, 



Cucumber, 



Muskmelon, 



Bean, 



Cyphomandra. 



The above categories comprise about all the species of 

 vegetables which are actually forced for market in this 

 country, and even of this short list there are a number for 

 which the market is so limited, or the methods of grow- 

 ing them so little understood, that they really have no 

 place in the staple demands of the market. Vegetables of 

 very minor importance as a forced crop are peas, carrots, 

 beets, cress, celery, eggplant, and pepper. In fact, there 

 are only three staple commercial forced vegetables, and 

 these, in the order of their commercial importance, are 

 lettuce, tomatoes, and cucumbers. 



