THE FLOWER GARDEN 315 



Great fields of grain have produced smaller 

 yields year after year until it was finally impos- 

 sible to grow a profitable crop at all. 



The remedy is rotation. 



Each grower must be his own doctor, however. 

 There is no short cut to profitable crop yields. 

 They are obtained by the man who understands 

 the bad effects of growing the same crop on one 

 field year after year, and who knows that these 

 effects can be avoided by making a change in 

 crops. 



Every horticulturist and every agriculturist 

 should study what follows carefully. It tells 

 why failures come, and why rotation forestalls 

 such failures. 



There are at least four important reasons why 

 rotation of crops is necessary. 



In the first place, insects which often gather 

 in great numbers about certain plants are de- 

 stroyed, or at least their number is reduced when 

 other crops are grown on the land. This is 

 because certain insects are adapted to depend 

 upon certain plants for their nourishment. 

 Lilies and amaryllis are often almost completely 

 destroyed by such insects as mites, small centi- 

 pedes, wire worms, eelworms, etc. 



Absolutely new, uncultivated soils seldom are 

 troubled. It is mostly in gardens where plants 



