204 TREES AND TREE-PLANTING. 
about eighteen inches apart, so as to allow of the young 
plants being cultivated without disturbing them. In the 
fall thin out the most vigorous and healthy, and trans- 
plant in a well-manured soil, in rows eighteen inches 
apart and the same distance from each other, where 
they should be allowed to remain until the fourth year, 
when they will probably have acquired half an inch or 
more in diameter, and of sufficient growth to bear the 
operation of grafting or trimming back. During the 
growth of the plants for the second and third years no 
knife should be used, especially on those shoots which 
occur a foot or more from the ground, but the soil upon 
which they grow should be kept perfectly free from 
weeds and subjected to repeated hoeings. 
