28 LAWNS 



base of the trees with stones loosely piled one 

 upon the other so that the air can have 

 free access. If possible make this stone 

 cylinder clear of the trunk by some few 

 inches. A wall of this type (see Plate xv) 

 will in nearly every instance preserve the tree 

 in its normal health. In the case of a tree 

 interfering with the slope of a terrace, the 

 same method should be employed making 

 the stone wall, however, only on the side where 

 it is necessary to retain the earth (Plate xv). 



UNDERDRAINAGE 



It is useless to attempt making a lawn on a 

 site that is so wet that it holds water in pools 

 after a rain. Wherever these conditions are 

 encountered a system of underdrainage must 

 be put in. The matter of tile draining is not 

 properly a detail of lawn construction, how- 

 ever, for it should be given attention in all 

 parts of estate construction. Drainage has 

 the effect of improving the fertility of the soil 

 by making it warmer, which also causes 

 vegetation to start earlier in the spring. From 

 these points alone it is a very essential detail in 

 all garden work. The bright green appear- 



