LETTUCE CULTIVATION AND IRRIGATION 203 



Planting. The distance between the plants in the field varies 

 from eight to fifteen inches. Where a variety producing large 

 heads, such as the Los Angeles, not less than twelve inches apart, 

 in rows twelve inches apart is best, but if a smaller variety the 

 spaces may be slightly reduced. If he seed has been sown directly 

 in the field the plants should be thinned when they are from two to 

 four inches tall, and the vacant spaces filled with those removed 

 while thinning. 



Irrigation. A few days before planting, the field should be 

 irrigated in order to settle the earth in the raised beds, and to show 

 how far up on them the water will come. If this is not done many 

 of the plants will be so high on the beds that they will not receive 

 sufficient water, while others will be so low that they will be in- 

 jured from an over-supply. As soon as the plants have been trans- 

 planted the field should be thoroughly irrigated, and it is especially 

 important while they are young that frequent irrigations be given. 

 In applying the water care should be taken that it is not allowed to 

 flow over the tops of the beds, and it will be found much more sat- 

 isfactory to use a small stream, allowing it to run between the beds 

 slowly, and thoroughly soaking into them, than a larger stream 

 flowing more rapidly. 



The number of irrigations which the field will require can only 

 be determined by the condition of the plants. It is sometimes de- 

 sirable to irrigate every week throughout the season, while under 

 other conditions one or two irrigations will be sufficient. There 

 should always be an adequate amount of moisture in the soil from 

 the time the plants have commenced to head until they have ma- 

 tured, because the character and size of the heads is influenced to a 

 great extent by the quantity of soil moisture present. 



During the late spring if it is desirable to hold the crop in the 

 field for a short time after it has matured, no more water should 

 be applied, as it will increase the liability of the plants going to seed. 



Cultivation. When raised beds are used all cultivation is done 

 by hand, the field being hoed from one to five times during the sea- 

 son, depending upon the soil, the weed growth, and the thorough- 

 ness with which the beds have been made and irrigated. The soil 

 need not be hoed between the beds unless there is a heavy growth 

 of weeds. Occasionally water will flow over the tops of the beds 

 and these low places should be hoed after each irrigaion if the soil 

 has a tendency to run together, for the growth of the plants will be 

 retarded if fye earth close to them is allowed to harden. 



Harvesting. The time required to mature a crop of lettuce va- 

 ries with the season, the character of the soil, and the care. Plants 

 set in the field during September should mature during November 

 and December. Plants set in the field during November will ma- 

 ture from February to April, inclusive, and those transplanted dur- 

 ing February and March will mature from April to June. 



