It has been the fashion among vine growers to prune their vines severely
in the month of July, taking off cart-loads of leaves and branches. The
reason given for this barbarous practice is that the grapes need
exposure to the sun and air in order to ripen, and that this stripping
off of the leaves and cutting away of the branches is necessary in order
to let the sun-light fall upon the fruit and the air circulate freely
among the clusters.
It is true that a grape vine may be allowed to produce too many branches
and leaves for the fullest development of the fruit, and the proper time
to guard against this is when the buds are starting into growth, by
rubbing out all superfluous eyes or buds as they begin to push forth.
But it is not true that the clusters of grapes require to be exposed to
the sun’s rays in order that the fruit may be ripened. The following
remarks by Dr. Lindley have a very direct bearing on this subject. He
says, “If all the leaves which a tree will naturally form are exposed to
favorable influences, and receive the light of a brilliant sun, all the
fruit which such a plant may produce will ripen perfectly in a summer
that is long enough. But if all the fruit which a healthy tree will show
is allowed to set, and a large part of the leaves is abstracted, such
fruit, be the summer what it may, will never ripen. The period of
ripening in fruit will be accelerated by an abundant foliage, and
retarded by a scanty foliage.” These general propositions he considered
applicable to all cases, and particularly to the vine. If correct, then
the severe summer pruning of the grape vine is wrong. “It is a mistake,”
he adds, “to imagine that the sun must shine on the bunches of grapes in
order to ripen them. Nature intended no such thing. On the contrary, it
is evident that vines naturally bear their fruit in such a way as to
_screen it from the sun_; and man is most unwise when he rashly
interferes with this intention. What is wanted is the full exposure of
the _leaves_ to the sun; they will prepare the nutriment for the grape;
they will feed it, and nurse it, and eventually rear it up into
succulence and lusciousness.”
The truth is this, that the leaves prepare the nourishment for the
grapes, without which they will never ripen, and unless there are
sufficient leaves so situated as to their exposure to the sun and air
that they can properly and abundantly supply this nourishment to the
fruit, it will never perfectly ripen. What is required then is not to
cut away the leaves and branches to let the sun-light in upon the
grapes, but to so thin out the shoots in the spring that the foliage
shall be well exposed to the full light of the sun, and if the whole
crop of leaves is allowed to remain that is thus exposed to the sun, the
preparation of the matter for the nutrition of the fruit will be more
rapid, and hence the ripening of the fruit accelerated. Hence if the
winter and spring pruning has been properly done there will be no
necessity for any summer pruning whatever.
But there is a pruning or rather stopping of the shoots in September
that is of benefit. On this subject Doctor Lindley says, “When, however,
in autumn the branches are beginning to slacken in their power of
lengthening, it is then right to stop the shoots by pinching off their
ends, because after that season newly formed leaves have little time to
do more than organize themselves, which must take place at the expense
of matter forming in the other leaves. Autumn-stopping of the vine
shoots is therefore not only unobjectionable, but advantageous, for the
leaves which remain after that operation will then direct all their
energy to the perfection of the grapes.”
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