28 
The Garden Magazine, September, 1920 
CONTRAST THESE TEN YEAR OLD UNPRUNED AND PRUNED PEARS 
The tree on the left is large, vigorous and bears abundantly, while the pruned 
tree on the right is much smaller and shows a profuse growth of suckers 
pruning treatment has entered in and destroyed the equality 
of the conditions. In the same way the unpruned trees have 
borne many more blossoms each spring, and are in every way 
better specimens. 
Finally, since these are strictly scientific as well as practical 
experiments, Professor Chandler does not rely on appearances, 
but accurately weighs the prunings from every tree touched, 
and carefully ascertains the leaf surface of every tree, every sea- 
son. “Some job’’ you may well remark; but it is providing con- 
vincing data in behalf of the new doctrine of “ Don’t prune unless 
you have to.” 
The Why of It 
city with which to furnish extra food to 
the developing fruit. Be there ever so 
much available nutrient material in the 
surrounding soil, the “smaller pump” 
cannot draw it in and distribute it. 
Now it is a significant thing that what 
Professor Chandler calls his most severe 
pruning system is considerably less heroic 
than the treatment given by the average 
commercial or amateur fruit grower. His 
unpruned trees, on the other hand, are 
practically untouched, except where a 
broken shoot or one that is clearly going 
to interfere with another more important 
branch, has to be removed. It is not 
surprising, therefore, to hear him say that 
in his opinion all fruit trees, even Peaches, 
are, as a rule, pruned too much in their 
early years. Of course Peaches come 
into bearing earlier than Apples and 
Pears and therefore can sooner be pruned 
without injury. 
In the same way, certain Apple and 
Pear varieties bear earlier than others, 
so that no hard and fast rule can be 
established as to when pruning becomes justifiable. Being 
a scientist engaged in scientific work — and being also a 
Missourian — Professor Chandler refuses to draw many deduc- 
tions from his experiments until he has an opportunity to prove 
them experimentally. So he grants that as far as he knows 
renewal pruning — even a severe cutting back — may be a very 
desirable practice in bringing old, mature trees to maximum 
bearing and keeping them there. For by reducing the leafage 
of such a tree you increase the available supply of moisture for 
the fruit. As to that, he is waiting to see. But he doesn’t 
hesitate to say emphatically that " The more you prune young 
fruit trees, the less growth they will make and the less they 
will bear.” 
N OW, as to the explanation. It is not at all difficult; in fact it 
is the most logical thing in the world, when you think of it. 
Pruning, says Professor Chandler, not only reduces the actual 
leaf surface of the plant at the time but also, by removing buds, 
reduces the leaf surface that would otherwise develop through- 
out the rest of the season. This, of course, lessens the capacity 
of the tree to transpire, or give off moisture from its leaf surface. 
Consequently the amount of water that the root system is called 
upon to supply is lessened. Similarly a smaller leafage calls 
for a smaller supply of the mineral nutrients that it is the busi- 
ness of the roots to send up in the sap. 
The result is that, throughout the season following the prun- 
ing, we have a plant with a root system considerably larger than 
its reduced top growth has need of. It is just as if we planned 
a lawn sprinkling system with say, twenty sprinklers and in- 
stalled a tank and pump big enough to handle them comfortably 
only to have someone come along and disconnect perhaps a 
dozen of the sprays and plug up their hose connections. Ob- 
viously the economical thing to do would be to install and 
operate a smaller pump. 
That is just what the pruned tree does — namely, install a 
smaller pump; or, less figuratively, check the development 
of its root system as the figures given above indicate. Naturally 
at the beginning of the next growing season we have a tree 
smaller in both root and branch area than it would have been 
if left alone; and in which note this — if now left unpruned, the 
roots will really be smaller than the new top will need for its 
fullest feeling and development. And if we keep up this prun- 
ing annually, the tree, when it begins to bear, will be to a cer- 
tain extent dwarfed and unable to produce a normally large 
crop. Even though we may try to stimulate it by means of 
fertilizers, the repressed root system will have no reserve capa- 
The Simple Rules for Modern Pruning 
H IS actual advice is, therefore, “ Prune your tree when you 
plant it, shaping the top and trimming back the roots to 
balance, as usually advised. From then on leave it alone, ex- 
cept for removing interfering branches, preventing the formation 
of undesirable crotches and doing any such absolutely essential 
pruning. Follow this system — or lack of system — until the 
tree comes into bearing; then begin to head back extra long 
shoots and thin out the center of the head gradually and care- 
fully until the desired height and shape are obtained. But 
in this, too, prune only where there is clearly need for the 
operation.” 
There, after all, is the crux of the matter: — Use the pruning 
knife as a controlling influence, riot as a stimulus, unless you 
have some unusual object in view such as extra large fruit, a 
peculiarly formed plant, etc.; and unless you are willing to pay 
for the result in lessened stature, reduced total yield or some 
such currency. That, of course, is what the Japanese plants- 
man does when he creates a tiny, distorted Pine after years and 
years of labor — he has what he set out for, but it has cost him no 
small sum. And what has it cost the tree? 
Grow your plant first, then let it come into bearing. That is 
the second lesson that I want this article to drive home. Dairy- 
men, horse breeders, dog fanciers — experts in all branches of 
animal husbandry — will tell you that to allow an animal to 
produce young while immature is inevitably to check its growth 
and dwarf its development. Exactly the same thing applies to 
plants; only, apparently, we have never realized it. Suppose, 
from now on, that we do give thought to this essentially na- 
tural principle and ponder carefully over both the pros and the 
cons of pruning before we start in on it. 
