252 ON PRUNING TIMBER TREES. 



take off each year the lateral shoots of one year, and never any 

 more. 



By this method we shall gradually denude the stem of its late- 

 ral branches from below upwards, while it is increasing in verti- 

 cal growth. The extent of clear trunk will thus gradually become 

 larger in proportion to the uncleared portion or top. Thus, sup- 

 pose we begin to prune when the tree has made fifteen years' 

 shoots, then when it has made thirty years' shoots, we shall have 

 cleared off fifteen; that is, half the height of the tree. 



Now, when we have cleared half the height of the tree, or a 

 very little more, we should pause in our further operations, and 

 mark its state of growth. If it continue to grow vigorously, we 

 may resume our operation of close pruning, but at longer inter- 

 vals than before, so as never in any case to have cleared away 

 more than one half, or at the utmost three-fifths, of the height of 

 the tree, and never taking off more than one years' lateral growth 

 of branches in a season. 



Every tree, it is observed, must possess a sufficient top ; that 

 is, it must extend horizontally as well as vertically, so as to bear 

 branches and leaves. The leaves are organs of nutrition of the 

 plant, essential to the healthy exercise of the vegetable functions, 

 and we must be careful to deprive it of no more of these organs 

 than consists with our purpose of pruning. Now, by proceed- 

 ing slowly in this gradual manner, never taking off more in 

 any one year, than the growth of one year's lateral branches, 

 we shall not usually interfere with the healthy growth of the 

 tree, but shall always leave it a sufficient power of expansion at 

 top, as to afford it the means of nutrition and growth. Further, 

 by never cutting off more at a time than the growth of one year, 

 the tree will generally have vigour to cicatrize the wounds that 

 have been made upon its trunk ; whereas, were we to lop off 

 many branches at a time, according to the practice too prevalent, 

 the tree might not have vigour to cover them with fresh growth 

 of bark, and thus the wounds might remain, to the lasting in- 

 jury and frequent destruction of the tree. 



In pruning in this manner the branches are to be cut off quite 

 close to the stem, so that the bark may quickly cover the wound; 

 and although trees may be pruned in summer, the fittest period 

 for pruning, as of all operations upon the living plant, when ve- 

 getation is inert : that is, from the fall of the" leaf, to the period 

 pf the ascent of the sap in spring. 



