130 



Nature-Study Agriculture 



Fertilizers 

 required 



When to 



grow 



lettuce 



W. T. Shilling 

 FIG. 107. Gathering a 5o-dollar crop of string beans in a school garden. 



it, and it is not able to break through a great thickness 

 of earth. The pea seed, on the other hand, remains 

 in the ground, and the tightly rolled plant pierces the 

 ground easily. Both beans and peas are usually planted 

 in drills, but the climbing varieties may be planted in 

 hills for convenience in arranging supports (poling). 



Beans and peas belong to the family of leguminous 

 plants. They do not require much nitrogen in the soil, 

 since, like all legumes, they can get it from the air through 

 the bacteria in their root nodules. But wood ashes, 

 ground bone, or any other fertilizers rich in potassium 

 and phosphorus are very beneficial. 



Lettuce. This vegetable, like cabbage, is a cool- 

 season crop. It thrives best in early spring or late 

 summer. It stands considerable cold. If grown in 



