VEGETABLES 383 



other frames and spaced two to three inches apart. As soon 

 as a new set of roots and leaves are put out, the plants are set 

 out in the field about six inches apart in rows three to four 

 feet apart. 



For blanching the early plants boards are used, which are 

 set up on edge beside the rows, brought together at the top, 

 and held by cleats. Late celery is blanched by banking the 

 earth against the plants, the banking being heightened two 

 or three times. 



Another common vegetable cultivated for its petioles is 

 rhubarb, which belongs to the buckwheat family (Poly- 

 gonaceae), and has various " docks " for its near relatives. 



Fruit 



89. Tomato. The tomato is a native of tropical America, 

 and this at once suggests that it is sensitive to frost and needs 

 warm and sunny soil and a long season. The fruit, which we 

 use as a vegetable, is really a berry, like currants and goose- 

 berries. The fruit was once called " love-apple " and was 

 thought to be poisonous, but now it is very extensively culti- 

 vated, and in North America, where it is grown more exten- 

 sively than in any other country, it has reached its highest 

 degree of perfection in desirable varieties. In the United 

 States it is grown more extensively for canning than any other 

 vegetable, a recent report stating that over 130 million cans 

 are packed each year, representing the cultivation of 300,000 

 acres. The leading states in tomato-production for canning 

 purposes are Maryland, New Jersey, Indiana, and California. 



Tomato is a member of the nightshade family (Solanaceae), 

 and its familiar associates are enumerated in connection with 

 the account of the potato (p. 370). 



Since the plants are very sensitive to frost, they are started 

 in hotbeds and transplanted as soon as the danger of frost has 

 passed. The plants are set four to five feet apart each way, 

 and in garden-cultivation they are usually " trained " to keep 



