PREPARATION AND CARE OF BEDS. 191 



if three or four inches of the surface soil are removed, and 

 the benches filled up with fresh manure, which should 

 be thoroughly worked into the soil. The best compost 

 for lettuce growing is made by mixing one part of fresh 

 horse manure with two parts of rich, sandy loam. If 

 t!iis can be prepared in June, and worked over in Au- 

 gust, it will be in good condition to use by the time it is 

 wanted in September. The raised beds will need about 

 five or six inches of soil, and after each crop has been 

 taken off, it will be well to add about an inch of thor- 

 oughly decomposed horse manure. The soil in the 

 solid beds shoald be ten inches deep, and should also be 

 top-dressed as above. 



After setting the plants, the beds should be thor- 

 oughly wet down, but while the plants are small care 

 should be taken not to saturate the beds, particularly 

 during dull weather in the winter. On sunny days the 

 plants may be syringed in the morning, but if they are 

 syringed in dull weather, or at the edge of evening, it is 

 likely to invite the development of mildew and rot. As 

 soon as growth starts, the bed should be worked over 

 with a hand weeder, and this should be repeated once in 

 two weeks, until the plants cover the bed (Pig. 73). 



The temperature of lettuce houses should be kept 

 below 50 degrees at night and in dull weather, while 45 

 degrees is high enough for the cabbage sorts at night. 

 The houses should be kept well ventilated, using the 

 sash that opens opposite to the direction of the prevailing 

 wind, whenever this is possible. Keep coolest just after 

 planting and when they begin to form heads. 



The most troublesome insect pest in lettuce grow- 

 ing is the green fly or aphis, but this can be kept in 

 check, if taken in time, by the use of tobacco stems. It is 

 well to cut them up by passing them through a hay- 

 cutter or coarse sieve, and then scatter the pieces over 

 the beds. The stems themselves can be used in the 



