Lettuce 



359 



that are very heavy, and particularly those that have 

 much clay, are ill -adapted to the crop. For the late 

 spring and summer crops the seed is usually sown rather 

 thickly and the thinnings are used on the table. The 

 plants that are to attain the largest size should stand 

 as much as a foot apart. 



Fig. 106. Lettuce as a companion-crop to cabbage. 



Successional sowings may be made as often as once 

 in ten days to three weeks. The earliest spring lettuce 

 taken from the open is usually started in frames or 

 forcing -houses, or sometimes in boxes in the house. If 

 one^s soil is moist, and particularly if the exposure is 

 somewhat cool, the ordinary spring lettuce may be 

 grown with success throughout the summer. In order 

 to secure a quick growth, it is sometimes advisable to 



