112 HAND-BOOK OF TREE-PLANTING. 



excluded from our native forests, we see the 

 young trees spring up thickly and grow in 

 close order, and, instead of spreading out their 

 limbs to a great extent near the ground, the 

 tendency is to shoot upward, making tall trunks, 

 the lower branches gradually withering and 

 dropping off. So we are told that in the for- 

 ests of Oregon and Washington Territory the 

 great trees often stand so close together that a 

 principal difficulty in converting them into lum- 

 ber is to find vacant space enough to allow their 

 fall to the ground when cut. Of course, these 

 giants of the wood, which have been growing 

 during one or even two hundred years, do 

 not stand within four or, perhaps, twenty feet 

 of each other. Nor is it meant, when we speak 

 of planting trees so close together, that they 

 are to preserve that closeness for a great length 

 of time. After a few years they will begin to 

 crowd each other and interfere with one an- 

 other. Then a thinning process must be com- 

 menced. At first one fourth may be removed ; 

 after a few years more, another fourth. The 

 general statement may be made that one half 

 of the trees should be removed before they 



