70 FRUIT-GROWING 



are encouraging the Hessian fly, but the fact 

 that you plow under your crop early in the 

 spring should reassure them. You are really 

 planting a trap crop which will protect their 

 wheat-fields. 



Men who advocate the use of some "sod 

 mulch" system of growing apples often have 

 ideas greatly at variance with one another. 

 One man may mean by the term merely the cut- 

 ting of the natural growth of weeds and grass, 

 while another implies the use of considerable 

 quantities of straw, hay or manure to reinforce 

 the mulch supplied by the natural growth. In 

 any event the object of the mulch is to conserve 

 moisture, just as that was the object of the dust 

 mulch in our system of cultivation. 



Often the only practical form of this sort of 

 mulch is the simple mowing of the weeds and 

 allowing them to lie where they fall. If the 

 growth is heavy this protection may be enough, 

 but if it is poor and light then the moisture 

 that will be held by such a covering will be 

 small indeed. 



The ideal grass mulch system would be one 

 where a very heavy growth of grass is cut and 

 allowed to lie so as to protect the whole sur- 

 face. But even then there would be disadvan- 

 tages for in such an orchard there would cer- 

 tainly be a good many ground mice to every 

 tree. It is the one pest for which we have no 



