ARBORICULTURE. 



327 



The Tree. 



Its Progression, Suppression and Retrogression. 



Beu'iiHiiii'! with tlie seed there is stored 

 u]; a considerable (|uantity of plant food 

 which is absorbed by the embr^'^otic plant 

 which enables it to make some ii})\var(l 

 growth, even before it has formed suttieieni 

 root to gather nourishment for support. 



But this is soon exhausted and the ]»lani 

 jnust rely entirely upon the food whicii 

 the rootlets gather from earth and raois- 

 tisre. 



The tirst few years of the tree's life uvc 

 occupied in extending its system of roots, 

 pushing them out in every direction where 

 the elements in the soil may be absorbed 

 by myriads of microscopic mouths and dis- 

 solved 1)\- water, carried upward to every 

 porti;on of the growing tree. 



In autumn, the sap with its load of 

 fo(»(K is clicmically changi'd by the atmos- 

 phere and descend'S to strengthen aiu! 

 extend the gro\\'ing root^. 



'I'he tree, beueatli the surface of the soil 

 is inuch more extensive than is the truni-: 

 and branches which are seen above ground, 

 fTud upon these unseen members the tree 

 must depend for its life support. 



Just so rapidly as the roots are enabled 

 to push through the soil and gather mois- 

 ture and nourishment will tlu' trunk and 

 branches progress. Ad\'ancing farther and 

 farther from the stem of the plant, each 

 step increases the area occupied by the nu- 

 merous rootlets, in geometric proportion, 

 and in the same pro]>ortion the trunk i:- 

 fcirced ujiward and branches extended. 



After a season the roots meet those from 

 surrounding trees and a struggle takes 

 place, nnseen, beneath the soil, for the pos^- 

 session of territory, for the limited quan- 

 tity of water which descends as rain, and 

 for the plant food which can not be util- 

 ized except in solution with water. 



Then comes sup])ression and the tree 

 remains, possibly for many decades, suftj- 

 ciently nourished to maintain life Init in- 

 suttioient for progression. 



Retrogression follows as a few of the 

 stronger overcome the more numerous 

 weaker, cro^\ding back the rootlets and 

 feeding upon them as they decay, until all 

 are destroyed except those whir-h arc fittest 

 to survive. 



During the tirst few years of life of an}' 

 tree, this underground, unseen portion is 

 the first to become established and the up- 

 ward nfovement is always disappointing, 

 unless thorough preparation and cultiva- 

 tioji of the soil takes place. 



As the roots gain in strength and in ex- 

 tent they are able to supply the energ-^ 

 which jurshes upward tlie visil)le portion 

 of the tree, and this action continues until 

 Clie roots are checked in some manner. 



EKROKS IN TREE PLANTING. 



Setting a tree in hard ground, without 

 sufficiently pulverizing the soil. 



Planting a tree in a hole of insufficient 

 size, whereby the young roots not able to 

 penetrate the hard earth, turn back and 

 coil about the tree as in a flower pot. 



Planting trees and failing to cultivate 

 them so that the rain can not penetrate 

 11 ic soil but runs of¥. 



Allowing grass and weeds to grow, thes^> 

 surface feeders absorbing all moisture. 



Any of which practices will stunt the 

 growth of trees by preventing proper ex- 

 tension of roots. 



Too close planting, which causes sup- 

 pression of growth, is tlie most prcAalenr 

 cause of failure. 



