LETTUCE 297 



well hardened off before being planted out; it will, however, 

 stand quite a severe freeze if properly hardened off, and, as 

 is the case with many other crops, the plants may be pro- 

 tected with earth on the approach of hard frost, providing 

 it does not remain over them more than a day or two. 

 In the open ground, lettuce plants should be set out about 

 t'.relve inches apart each way. It is frequently grown 

 between rows of early cabbage, cauliflower, or other plants 

 where it fills up otherwise unoccupied space and comes off 

 the land long before other crops need the room it occupies. 

 For late use the seed is often sown in the open ground in 

 drills one foot apart and the plants thinned to the same 

 distance apart. It is customary also in the home garden 

 to sow the seed and then cut off the young plants as soon 

 as they are large enough to use; such lettuce, however, is 

 not nearly so good -as head lettuce, where the center is 

 white, crisp, and tender. It is a far better plan to thin 

 out the young plants so that they stand three or four 

 inches apart in the rows, and, in cutting, continue the 

 thinning process so that the later plants will form good 

 heads. Of course, it is necessary to make successive sow- 

 ings of lettuce in order to have it fit for table use over a 

 long season. Like all leaf crops, lettuce needs plenty of 

 rich, easily available nitrogenous manure, and responds 

 very quickly to small applications of nitrate of soda. 



Seed. Most of the seed of lettuce used in this country 

 comes from California. Several hundred acres are grown 

 there for seed. It is said thirty to sixty plants will produce 

 a pound of seed. Great care should be exercised in the 

 purchase or growing of lettuce seed if large quantities of 

 lettuce are to be grown. 



Varieties. There are many varieties, and each year 

 finds many additions to the list of those offered by seeds- 



