6 THE POPULAR SCIENCE MONTHLY. 



fully as important for the most rapid and healthful growth of trees 

 as for the growth of the ordinary crops of the garden or the field. 

 For this purpose they construct open ditches at intervals throughout 

 the forest. In our natural forests, filled with the roots of old trees 

 and often with rocks, it would be difficult to make such ditches. But 

 in many of our low and swampy lands it would be quite practicable, 

 and would add greatly to the amount and value of the growing wood. 

 There is no reason why one should not incur the expense necessary 

 to drain the soil for trees as readily as he does that which he considers 

 desirable for his grass or corn ; and all who undertake the planting of 

 trees on new ground should bear this in mind. 



We are writing now to urge the importance and even necessity of 

 planting trees on the large scale, as well as the preservation and care 

 of our existing native forests ; and one of the first questions to be set- 

 tled is that of the distance which should separate trees from each other 

 at the time of planting. The experience of European planters has 

 satisfactorily proved that they should be planted much nearer to one 

 another than they are to stand when fully grown. In this respect they 

 should be planted not like the apple or peach orchard, but like the 

 corn-field. One reason why the law of Congress for the promotion of 

 tree-culture has not been more successful is that it allowed trees to be 

 planted twelve feet apart. Trees, when young, are delicate things, 

 and need protection. Like human beings, they seem to have a feeling 

 of companionship. They support and encourage one another. They 

 thrive best when near each other. Accordingly, European foresters 

 commonly plant trees at a distance of not more than four feet apart, 

 and some of our Western planters are disposed to place them even 

 closer than this. Such close planting follows the course of Nature. 



If we observe a natural forest, from which destructive animals are 

 excluded, we shall see that the ground is thickly strewed with trees 

 that few large vacant spaces are to be found, especially when the trees 

 are small. As they increase in size and need more space, Nature has 

 her own way of thinning out. The weaker decay, and the law of the 

 survival of the fittest asserts itself. Following her guidance we have 

 learned to plant closely, and then, from time to time, to make room 

 for the growing trees by transplanting a portion to other fields, or by 

 cutting them and devoting them to such uses as they are fitted for. 

 The smaller serve for hoops for the barrel-maker, or poles for various 

 uses. And so, at all stages of growth, there is an available and profit- 

 able use for the trees that seem to be crowding their neighbors. 



It is found, again, that trees are not only social in their nature, but 

 that they like variety in their society. As a general thing, different 

 kinds of trees grow better when mixed together than when each kind 

 is planted by itself. This, also, is usually Nature's way of planting. 

 It is common, therefore, for the foresters abroad to plant what they 

 call nurse-trees along with those which they intend to make the staple 



