PLACING STREETS ANB AVEKtJES. 77 



ings on the other, their roots must of course ramify for 

 many feet underneath these surface obstructions. Aside 

 from this the soil is apt to be of the poorest. It is 

 hardly to be expected, in such circumstances, that a 

 thrifty growth can be secured without something being 

 done to offset these drawbacks. Liberal supplies of fer- 

 tihzers, especially potash salts and nitrates, ought to be 

 worked into the soil whenever the surface is accessible. 



It is a good plan to set street trees rather close 

 together in the beginning, and to thin them as they 

 grow and begin to crowd. This plan, however, demands 

 very conscientious attention to the thinning, for some- 

 times it is a matter of considerable heroism to cut out 

 strong, thrifty trees along the avenue when they are 

 only beginning to crowd their neighbors just a little. 

 But any undue procrastination is sure to damage the 

 survivors very seriously. 



The distance between trees in the row will be influ- 

 enced somewhat by the width of the street. In a wide 

 street, where there is room enough for the full develop- 

 ment of each tree, they will be planted farther apart. 

 If the street is wide enough, the trees should always 

 stand between the walk and the curb. It is wide enough 

 if, from curb to curb, tlie width is one and a half times 

 the distance recommended for the trees in the rows. 

 On a narrower street, trees should stand between the 

 walk and the buildings or should be dispensed with. 

 There are many beautiful streets in this country which 

 support four rows of trees. Such streets should have 

 the central avenue twice as wide as the distance between 

 trees in the row ; and the distance between the two 

 rows on either side should be somewhat less than that 

 between trees. 



If, now, we are seeking a formal effect in our rows 

 of street trees, it follows that this effect will be empha- 

 sized by trees which naturally assume somewhat formal 



