GARDENERS' CHRONICLE 



OF AMERICA 



DEVOTED TO THE SCIENCE OF FLORICULTURE AND HORTICULTURE 



ADOPTED AS THE OFFICIAL ORGAN OF 



THE NATIONAL ASSOCIATION OF GARDENERS 



fiiOTANJCA.- 



Vol. xix'V/ 



FEBRUARY, 1913. 



Xo. 4. 



The Principles and Practice of Pruning 



By Arthur Smith. 



There are few, if any, of the operations connected with 

 forestry, horticulture, or agriculture, which are not capa- 

 ble of being explained by scientific principles, these prin- 

 ciples being based upon natural laws. 



The laws of nature are constant and unvaried in their 

 operations. Our knowledge of them has gradually been 

 built up by observation and experiment, involving a true 

 appreciation of the relations between cause and effect, 

 and science in its truest aspect gives a systematized ex- 

 planation of the results of these observations. At the 

 same time the more one knows of these scientific princi- 

 ples the greater is the apparent size of the unexplored 

 field. 



The operation of pruning is therefore based upon cer- 

 tain well-defined principles, derived from the accumulated 

 knowledge acquired by many years of observation of 

 the effects produced by cutting away, etc., the branches 

 and other parts of plants. 



These principles mainly divide themselves into two 

 objects which are carried out by removing portions of the 

 plant for, (1) lessening the struggle for existence amongst 

 the branches by the prevention of overcrowding, and for 

 (2) assisting nature by bringing about certain desired 

 effects which may be increase or decrease of wood ; in- 

 crease of quantity and quality of -flowers and fruit or 

 making a more shapely and better balanced head. In a 

 state of nature, plants — by which term we mean every- 

 thing from the largest forest trees downwards — produce 

 many more branches than persist, and dead and dying 

 branches are evidences amongst other things, of nature's 

 pruning. In Forestry the ideal is to produce long, 

 straight, clean timber : this is brought about by planting 

 closely, thereby causing nature to prune off the side 

 branches when they are very young, thus preventing the 

 formation of knot holes, and causing the maximum 

 . amount of growth to go into length of trunk. When a 

 large branch dies or is cut oft" there is a liability for the 

 resulting decay to penetrate into the trunk, especially if a 

 stub of any length remains. This is why it should be cut 

 off close to the truilk so that the bark cart grow over and 

 heal the wound. To prevent decay while the hark is ac- 

 complishing this, a covering of paint or tar should always 

 he applied and also the rough edge on the bark caused by 

 the saw should he shaved smooth by a sharp knife. This 

 latter operation causes the cambium or inner bark, which 

 is the living portion, to start new growth more quickly. 



Lessening the struggle for existence amongst the 

 branches causes the remainder to receive more food and 

 energy, thus rendering them capable of producing more 

 flowers and fruit, and, what is of the greatest importance, 

 fruit of better quality. 



When we take into consideration the period during 

 which pruning has been practiced, and the countless repe- 

 titions of similar actions, invariably ending in similar re- 

 sults, there is nothing unreasonable in assuming that a 

 sufficient number of facts have been observed to establish 

 a complete science or code of laws, the practical applica- 

 tion of which is easily carried out. But, like all other ap- 

 plications of science to an art, the operation of pruning 

 must be performed from an intelligent standpoint. In 

 this connection one must be careful to take into considera- 

 tion all facts and circumstances which may be called 

 ■■fixed." such as soil, climate, species of tree, and whether 

 the object to be achieved is fruit or timber : a tree for 

 ornamental or utilitarian purposes. 



It is therefore impossible to lay down hard and fast 

 rules of universal application. For instance, it is gen- 

 erally well known that different varieties of apples on the 

 same soil call for somewhat dift'erent treatment in the de- 

 tails of pruning ; also that the same varieties on another 

 soil do not give similar results with the same method. 

 This is no doubt the caiise for the various opinions which 

 exist among orchardists in respect to many of the details 

 of this operation. A man who for many years has 

 adopted a certain method with success in one locality, is 

 apt to jump to the conclusion that his system is applica- 

 ble everywhere. Such is not always the case. While the 

 underlyin.g principles are fixed their application nnist har- 

 monize in detail with one's environment. 



In this connection I am afraid we do not experiment 

 enough ourselves. By taking several trees of a given 

 variety and giving them dift'erent treatment in the way 

 of pruning, taking care that all other things are equal, 

 we should ultimately arrive at a more or less correct so- 

 lution of the problem as connected with our own individ- 

 ual conditions. 



It is impossible to over-estimate the importance of 

 pruning, or perhajis we should say, when and how to 

 prune and when not to prune at all. In the management 

 of plants in general, and in fruit culture especially, com- 

 plete success is not attained unless the principles are clear- 

 ly understood. 



In nature there is a more or less general balance kept 

 u]). and a constant reciprocal action going on between 

 branches and roots ; and no one should prune without be- 

 ing satisfied of a reason for doing so, and of foreseeing 

 the influence and ultimate effect of such pruning. 



.\s regards fruit, some growers say that the most satis- 

 ffictorv average crops arc produced in those orchards 

 where little, if any, pruning is done at all. Instances of 

 this no doubt exist, especially in the case of trees 25 or 

 more years old, but in all probability their present state is 



