226 CROP GROWING AND CROP FEEDING 



growers are troubled with long, sunless spells, it has been found profitable 

 to string arc lights over the houses for forcing the crop. This is a refinement 

 in horticulture that few will imitate. The culture of frame lettuce will be 

 more fully treated in chapter on cold frames. 



LETTUCE IN THE OPEN GROUND. 



This is the crop that most farmers are more interested in than the forced 

 crop. Anywhere from Virginia south lettuce plants can be safely wintered 

 over outside with slight protection of manure in the northward section. In 

 the North, however, it is best to winter the plants over in frames, as cabbage 

 plants are there carried over. The market gardener, with his costly and 

 fertile land will get the early outdoor crop from plants set between the cab- 

 bages, and will have it out of the way before the cabbages need all the room. 

 Otherwise the plants are set as soon as the ground can be worked in the 

 spring, in well enriched soil, and make a good crop to be followed by some 

 tender plants, which cannot be set till the ground is warm. 



THE MANURIAL REQUIREMENTS OF LETTUCE. 



Lettuce, like most foliage crops, needs an abundant supply of nitrogen, 

 and also in the soil it prefers, a light, sandy loam, a large percentage of pot- 

 ash with a fair proportion of phosphoric acid; though this is of less import- 

 ance than the first two. Occupying the soil during the winter months, when 

 there is not a great activity among nitrifying organisms, it is essential that 

 the fertilizer be presented not only in lavish amount, but in a perfectly solu- 

 ble form. Hence for frame lettuce we would make a mixture of acid phos- 

 phate, 900 pounds; dried blood or fish scrap, 600 pounds; nitrate of soda, 100 

 pounds, and muriate of potash, 400 pounds. The large percentage of potash 

 renders it necessary, as we have said, that the fertilizer be applied some time 

 before setting the plants, usually one month. But the nitrate of soda should 

 be reserved and not mixed with the other ingredients, but scattered between 

 the rows after the plants begin to grow. The first frame crop set in the 

 South in October, will need no protection till the later part of its growth, 

 in late November and December, but the projection should be at hand for 

 the first cold snap. 



VARIETIES OF LETTUCE. 



The varieties used by the growers of winter lettuce are few. The mar- 

 kets of the Eastern States demand a well headed lettuce, while in the West 

 the curled and loose headed sorts are popular. For the fall crop we prefer 



