Summer Pruning : Theory and Practice. 
Part I. 
FFECTS OF PRUNING.—A common saying is 
“prune for wood in Winter and for fruit in 
Summer.” This may be expressed in other words 
to the effect that 
pruning in Winter en¬ 
courages wood growth 
while pruning in Sum¬ 
mer encourages fruit 
production. The fact 
that Winter or dormant 
season pruning results 
in a tendency to in¬ 
crease wood growth is 
readily made plain. 
THE TREE’S FOOD 
RESERVE.—Fruit trees 
store up starch in the 
late Summer and Fall 
as a reserve food sup¬ 
ply to draw upon in 
early Spring for the 
formation of leaves and 
flowers. Suppose a tree 
has developed 1.000 
buds before Winter. A 
certain amount of 
starch has been stored 
to meet the needs of 
these buds when growth 
begins the following 
Spring. Now if 500 of 
these buds are cut away 
in a pruning process 
the remaining 500 buds 
will have about double 
the amount of reserve 
food to assist in their 
development, with the 
result that a more vig¬ 
orous growth t a lies 
place. When does this 
reserve supply become 
exhausted? In the case 
of the peach it is near¬ 
ly used up in growth by 
June 1, or by the time 
the young fruits are 
about three-quarters of 
an inch in length. After 
this the tree must de¬ 
pend upon the plant 
food elaborated daily for 
its support. The leaves 
are the digestive sys¬ 
tem of the tree. Crude 
plant foods are taken 
up by the roots but 
must then be transferred 
to the leaves for “di¬ 
gestion” or elaboration. 
FORMS OF SUM¬ 
MER I* It U N I N G.—A 
common statement is 
that Summer pruning 
checks wood g r o w t li 
and therefore promotes 
fruit bud formation. It 
said to check the growth of the tree because of the 
reduction of its power to manufacture starch and 
sugar. This is clearly demonstrated when a tree 
is defoliated by insects or disease and then the ef¬ 
fect of a partial defoliation may be expected to be 
in direct proportion to its relative severity. 
Effect of Cutting Tip of Apple Twig in Growing Season. Fig. 351. 
• ■ V 
. ?Sli * V -- 
* .. >*■ 
is evident that there may be at least two forms of 
Summer pruning, the removal of entire branches, 
twigs or shoots, or the pinching or cutting back of 
shoots. The former may result in removal of con¬ 
siderable foliage, the latter of scarcely any. The 
removal of any considerable amount of foliage is 
Pinching Back the Tips Makes the Top More Dense. Fig. 352. 
removal of a few small twigs or shoots, however, 
may have little or no economic effect. 
“THICKENING” THE TOP.—The cutting back of 
a twig in the dormant season results in the develop¬ 
ment of several branches below this point and 
“thickens” the top of the tree. Pinching or cutting 
back the tips of growing shoots in the Summer 
checks the growth of the shoots for a time until side 
buds can be developed and branch growth resumed. 
Pinching the tips of growing shoots therefore re¬ 
sults in the production of more branches and “thick- 
The ens” the tops of trees in Summer as does the cutting 
back of tips of branch¬ 
es in Winter as illus¬ 
trated in Fig. 351. One 
prunes a privet hedge 
in early Spring before 
growth begins and once 
or twice during the 
Summer to secure a 
much branched compact 
growth. 
MORE AND BET¬ 
TER FRUIT.—F ruit 
trees are grown with 
the idea ot securing the 
largest amount of per¬ 
fect fruit possible. The 
bulk of our fruit pro¬ 
duction is also upon a 
commercial basis and 
cost of production must 
be kept as low as possi¬ 
ble to make a profit. 
Any orchard operation 
then which does not re¬ 
sult in a profitable 
money return, either di¬ 
rectly or indirectly, sim¬ 
ply becomes an added 
a n d unnecessary ex¬ 
pense. 
FADS IN PRUNING. 
—A system of pruning 
is too often adopted be¬ 
cause it meets the the¬ 
ories or fancy of the 
grower when it has no 
definite known basis of 
tree welfare or direct 
com m erci a 1 profits. 
Trees are pruned to 
many shapes and forms 
and prolonged discus¬ 
sion often arises as to 
the merits of one type 
over another. Too often 
is it a case of whether 
a brown-shelled egg is 
any richer than a white- 
shelled one. Too often 
is it regarded as purely 
an art rather than a 
science. 
FRUIT PRINCI¬ 
PLES.—The objects of 
pruning fruit trees may 
be grouped and consid¬ 
ered from the following 
standpoint: 
1. Factors which con¬ 
cern the mechanical 
strength of the tree. 2. 
Factors which concern 
the distribution of the 
fruit-bearing surface. 3. 
Factors which concern the vigor and life of the tree. 
4. Factors which concern the strictly commercial 
interest. 
The mechanical strength of any particular habit 
of tree growth and modification to meet the strain of 
a heavy load of fruit may be a pruning problem in 
