112 FOBESTKY WOKK 



Trees to plant Pure. 



Shade-bearing trees such as Spruce, Silver Fir, Douglas 

 Fir, Beech, and Hornbeam, should be grown pure where 

 their timber is most in demand and the soil is most suited 

 to them, because no other trees grown in mixture with 

 them would prune them sufficiently to produce high- 

 class timber. Mixtures of two or more shade-bearers 

 are seldom satisfactory, as their height growth is so 

 unequal. 



Light-foliaged trees may be planted and allowed to 

 remain pure for a number of years, and then heavily 

 thinned, and underplanted with some shade-bearing and 

 soil-protecting tree. 



Methods of Mixing. 



There are three main methods of mixing viz., (1) By 

 single trees; (2) by groups or patches; (3) by strips. 



1. Trees such as Oak or Chestnut are planted from 

 12 to 15 feet apart and the intervals rilled up with nurses, 

 that will be removed as thinnings. Two or more varieties 

 may be mixed singly in the lines. 



2. Small groups or patches of light-foliaged trees may 

 be planted, and the spaces between filled up with soil- 

 improvers. Variations in the soil, too, may be taken 

 advantage of to plant species to which each class is 

 suited. 



3. Strips from 5 to 20 lines wide may be planted 

 alternately with light-demanders and shade- bearers. 



The strips should run from east to west, so that the 



