Care Of The Vines
With the cultivation of all varieties indoors, more clusters set than
the vines can carry. This means that a part of the clusters must be
removed, an operation that depends on the variety and one that
requires experience and judgment on the part of the gardener. Roughly
speaking, half the clusters are taken, leaving the other half as
evenly distributed on each side of the vine as possible. The time to
take these cluste
s is also a delicate matter, since some sorts are
shy in setting and the clusters must not be taken until the berries
are formed and it can be seen how large the crop will be. As a rule,
however, this thinning of clusters may be begun as soon as the form of
the cluster can be seen.
It is very necessary also, especially with all sorts bearing large
berries, that grapes be thinned in the cluster. The time to thin the
cluster varies with the variety. Sorts which set fruit freely can be
thinned sooner than those which are shy in setting. On the one hand,
the thinning must not be done too soon as it cannot be told until the
berries are of fair size which have set seed and which have not;
however, if thinning is neglected too long, the berries become
over-crowded and the task becomes difficult. The thinning is performed
with slender scissors, and the bunches must not be touched with the
hand, as touching impairs the bloom and disfigures the fruit. The
clusters are turned and steadied by a small piece of pencil-shaped
wood. Thinning is practiced not only to permit the berries to attain
their full size but also to permit the bunches to attain as great size
as possible. If too severely thinned, the clusters flatten out after
maturity. This is especially the case when too many berries are taken
from the center of the bunch. A large cluster of grapes is made up of
several small clusters, making it necessary to tie up the upper
clusters or shoulders of the bunch to permit the berries to swell
without being thinned too severely. Grapes intended for long keeping
require more thinning than those to be used at once after picking,
since, in keeping, the berries mold or damp-off in the center of the
bunch if it is too compact.
The vines in the grapery must be watered with considerable care. The
amount of water to be used depends on the composition of the borders
and the season of growth. If the border is loose and well-drained, the
supply of water must be large; if close and retentive, but a small
amount of moisture is required. Watering must not be done during the
period of blossoming, since dry air is necessary for proper
pollination. When the grapes begin to show color, the vines are
heavily watered, after which little if any water is applied. Some
gardeners mulch the vines with hay to retain the moisture in the house
and keep the atmosphere dry.
Ventilating the grapery is another important detail of the season's
work. Proper ventilation is difficult to secure in the early spring
months when the dryness of the sun on the one hand, and cold air on
the other, make it difficult to avoid draughts and regulate the
temperature. Another troublesome time is when the grapes begin to
color, as it is then necessary for the grapery to have air at night;
but when too much air enters, there is danger from mildew. Towards the
end of the season, all parts of the plant become harder in texture and
the grapery may then be more generously aired. After the fruit is cut,
the houses are ventilated in full so that the wood may ripen properly.