282 GARDEN FARMING 



In the vicinity of Charleston, lettuce and cucumbers are used in 

 succession under muslins or muslin-covered frames, but south of 

 that point lettuce growers depend on natural conditions. The pro- 

 duction of lettuce under muslin involves certain difficulties which 

 cannot be dealt with as economically and as satisfactorily as in 

 forcing houses. Yet because of the small expense involved in the 

 erection and maintenance of cloth-covered frames, a grower can 

 afford to take chances which would not be justified under glass. 

 When successfully grown under muslin the crop is nearly if not 

 quite equal in appearance to that grown under glass, but it is 

 doubtful if its quality is as good. This is an open question and 

 must be decided by each consumer. 



LETTUCE AS A FORCED CROP 



The forcing of plants, as previously defined, consists in growing 

 them out of their normal season. Lettuce when grown in green- 

 houses, hotbeds, or cold frames at a season when it cannot be 

 grown in the open is a forced crop. No other salad plant and 

 no other garden vegetable is so extensively forced as lettuce. 



In the neighborhood of the large Eastern and Northern cities 

 acres of land are covered by glass for the purpose of forcing this 

 crop. The improved varieties of head and cutting lettuce, when 

 grown under glass, possess a delicacy of texture and flavor which 

 cannot be developed even by the most careful culture in the open ; 

 and for this reason the products of the large forcing establishments 

 find a ready sale in the large cities where the superiority of such 

 products is understood and appreciated. 



Lettuce being a cool-season crop requires a forcing house, the 

 temperature of which can be so maintained as to approach closely 

 the normal spring conditions under \vhich the crop thrives best. 



The greenhouse. The majority of the houses constructed for the 

 cultivation of lettuce are nowadays of the even-span type. They 

 are usually frame structures from 4 to 6 feet high at the eaves, 

 with glass sides carried to within 15 or 1 8 inches of the ground, 

 the height of the ridge depending upon the width of the house. 

 No benches are used, the beds being constructed on the surface 

 of the soil. Paths are usually provided along the outside wall, 



