Staking, Training and Pruning
Under favorable conditions of soil and climate, plants of most varieties
of tomatoes will, in field culture, yield as much fruit if allowed to
grow naturally and unpruned as if trained and pruned. This is especially
true of the sorts of the Earliana type and on warm, sandy soils, while
it may not be true of the stronger growing sorts, or on rich clay lands
or where the fertilizer used contains an excess of nitrogen. In any case
more fruit can be grown to the acre on pruned and staked plants because
more of them can be gotten on an acre; and it is an advantage to grow
them in that way because it enables us, by later cultivation, to keep
the ground in good tilth longer; also it facilitates the gathering of
the fruit; and last, but not least, it generally enables us to produce
better ripened and flavored fruit.
Staking and pruning used to be the almost universal practice in the
South, but in many sections growers have abandoned it, claiming that
they get as good or better results without it. In the North it is rarely
used in field culture, though often used in private gardens and by some
market gardeners, and both staking or tying up and pruning are essential
to the profitable growing of tomatoes under glass. In the South, stout
stakes from 1 to 2 inches in diameter and 4 to 5 feet long are driven
into the ground so that they can be depended upon to hold the plants
erect through the heaviest storms, as seen in Fig. 21. This is generally
and wisely done as soon as the plant is set, though some growers delay
doing so until the fruit is well set, claiming that the disturbance of
staking, tying and pruning tends to hasten the ripening of the fruit.
The plant is then tied up, the tying material being wrapped once about
the stake and then looped about the plant so as to prevent slipping on
the stake or choking the stem of the plant as it enlarges. Raffia is
largely used and is one of the best tying materials, but short pieces of
any soft, cheap string can be used. The tying up will need to be
repeated as the stem elongates, which it will do very rapidly.
In pruning the tomato we should allow the central shoot of the young
plant to grow, and remove all of the side shoots which spring from the
axils of the leaves and sometimes even from the fruit clusters, as seen
in Fig. 22. It is very desirable that this be done when the branches are
small, as there is then less danger of seriously disturbing the balance
of the growing forces of the plant, and also because there is less
danger of careless workmen cutting off the main shoot in place of a
lateral, which would seriously check the ripening of the fruit. It is
especially important that any shoots springing from the fruit cluster be
removed as early as possible. For these reasons it is important that, if
the plants are to be pruned at all, the field be gone over every few
days. If the pruning is not well done it is a disadvantage rather than a
help.
[Illustration: FIG. 21--TRAINING TOMATOES IN FLORIDA TO SINGLE STAKE
(Photo by courtesy of Prof. P. H. Rolfs, Director Florida Experiment
Station)]
[Illustration: FIG. 22--TOMATO PLANT TRAINED TO SINGLE STAKE]
[Illustration: FIG. 23--METHOD OF TRAINING TO THREE STEMS IN
FORCING-HOUSE AND OUT OF DOORS]
Some growers allow two or three (Fig. 23) instead of one shoot to grow,
selecting for the second the most vigorous of the shoots starting from
below the first cluster of fruit. In some locations they stop or pinch
out the main shoot just above the first leaf above the third or fourth
cluster; in some soils it is an advantage and in others rather a
disadvantage to do this. I have seldom practiced it. When fruit at the
lowest cost a bushel is the desideratum, neither pruning nor staking is
desirable.
[Illustration: FIG. 24--METHOD OF TRAINING ON LINE IN GREENHOUSE]
[Illustration: FIG. 25--READY TO TRANSPLANT IN GREENHOUSE (Redrawn from
photo by New York Experiment Station)]
[Illustration: FIG. 26--TRAINING YOUNG TOMATOES IN GREENHOUSE AT NEW
YORK EXPERIMENT STATION (Photo by courtesy Prof. U. P. Hedrick)]
=For home gardens.=--In the home garden trellising and pruning are often
very desirable, as they enable us not only to produce more fruit in a
given area but of better quality. Many forms of trellis, have been
recommended. Where the plants are to be pruned as well as supported, as
they should always be in gardens, there is nothing better than the
single stake, as described above. For a trellis without pruning, one
to three stout hoops supported by three stakes so as to surround the
plant which is allowed to grow through and fall over them, or two or
more parallel strips supported about a foot from the ground on each side
of a row of plants answer the purpose, which is simply to keep the plant
up from the ground and facilitate the free circulation of the air among
leaves and fruit.
[Illustration: FIG. 27--TOMATOES IN GREENHOUSE AT OHIO EXPERIMENT
STATION (Photo by courtesy of C. W. Waid)]
I have seen tomatoes grown very successfully by the side of an open
fence. Two stakes were driven into the ground about 6 inches from the
fence and the plant, but slanting outward and away from each other. The
tops of the stakes were fastened to the fence by wooden braces, and then
heavy strings fastened to the fence around the stakes and back to the
fence, the whole with the fence forming a sort of inverted pyramidal
vase about 3 feet across at the top. In this the plant was allowed to
grow, but it would be essential to success that the fence be an open
one.
[Illustration: FIG. 28--FORCING TOMATOES IN GREENHOUSE AT NEW HAMPSHIRE
EXPERIMENT STATION. NOTE CHARACTER OF BED ON THE GROUND FLOOR. (Photo by
courtesy of Prof. H. F. Hall)]
=In the greenhouse.=--Here pruning and training are essential. The
plants may be supported by wires or strings (a coarse wool twine will
answer), twisting the string about the plant as it grows. The growth is
usually confined to a single shoot, though some growers allow two (Fig.
24); the method of pruning does not differ from that given for field
culture, but it is more important that the plants be gone over often
and the branches removed when small. If allowed to do so, branches would
spring from the axil of each leaf and the plant would become a perfect
thicket of slender branches and leaves and produce but little fruit. The
main stem is sometimes pinched out after three or four clusters of fruit
are set and the branch from the axil of the first leaf above is allowed
to take its place. This tends to hasten the maturing of the fruit
clusters already set. After several clusters have matured, or the main
stem reaches the top of the house, some growers allow a shoot from the
bottom to grow and as soon as fruit sets on it the first stem is cut
away and this takes its place. Others prefer to remove the old plant
entirely and set in young ones. A plant ready for transplanting is shown
in Fig. 25. In figures 26, 27 and 28 are shown interior views of
greenhouses at the New York station at Geneva, the Ohio station at
Wooster, and the New Hampshire station at Durham. Note the strong,
vigorous plants in Fig. 26; the method of utilizing tile for watering in
Fig. 27; and the ground-floor bedding in Fig. 28.