OF VEGETATION. 287 



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allowed in the present times, in order to improve the ap- 

 pearance of a tree, is to strip off the lower branches, in, 

 order to prevent its assuming the form of a bush. This 

 operation should not be performed too soon : the stem, 

 while young, requires the aid of these lower branches to 

 carry on the process of vegetation, and supply it with 

 nourishment : they pour their cambium into the stem at 

 its base, and thus assist in increasing its vigor. 



Emily. Yet, would not this operation become danger- 

 ous, if long delayed ? for the larger the lower branches are 

 suffered to grow, the more serious will be the effect of 

 their amputation. 



Mrs. B. The proper time for lopping them is, when 

 the tree has attained sufficient vigor to enable it to recover 

 from the wounds, in the course of the year. 



Resinous trees suffer from pruning, by losing too much 

 of their resinous juices : fir trees should never be pruned ; 

 but if planted in groups, as we see them growing natu- 

 rally, the lower branches, being deprived of light and air, 

 dry up and perish : it is thus that Nature prunes them 

 without the infliction of a wound, from which the resinous 

 juices would flow, to the great detriment of the plant. 



In regard to the pruning, which relates to the health 

 of plants, not only should all the dead branches be care- 

 fully removed, but the pruning knife must penetrate into 

 the quick of the wood. It is advisable, also, to cut away 

 all the parts which are diseased, as these seldom recover, 

 and would continue, during a few years of sickly exis- 

 tence, to absorb, uselessly a portion of the sap, and very 

 probably, during this period, to communicate their mala- 

 dy to the contiguous branches. 



All branches seriously injured by hail, should be imme- 

 diately removed ; they will then rapidly shoot afresh, and, 

 in the course of a few weeks, their loss will not be per- 

 ceived. 



Emily. Greenhouse plants must require a great deal 

 of pruning, for as their roots cannot grow freely in search 

 of food, the branches must be diminished, in order to 

 correspond with their limited quantity of nourishment. 



1548. What is the present mode of improving their appearance? 

 1549. Why should this operation not he performed too soon. 1550. 

 Of pruning resinous trees what is said! 1551. How should pruning 

 be done, which relates simply to health 1 ? 1552. Of diseased parts 

 what is said"? 1553. And of branches seriously injured by hail! 



