How To Prune Tomatoes in the UK
Tomato Plants to
As far as pruning is concerned, tomatoes in the UK come in two forms, bush (or
determinate) and upright (indeterminate or cordon). The difference between the two types of
tomato plants is that bush varieties naturally produce a limited amount of side stems, they
"know" when to stop producing foliage and when to start producing tomatoes. For this reason
they need very little pruning.
On the other hand, upright tomato varieties don't really know when to stop
producing and if left alone they will produce far too much foliage and too few tomato
fruits. Careful and frequent pruning will help them stop producing foliage at the correct
time and they will then produce a much better crop of edible tomatoes.
Bush varieties do well for cultivation outdoors because they
require little pruning for most of the season. Remove any yellow or decaying
foliage as soon as possible to avoid the spread of disease.
It's also a good idea to prune any stems that are touching or very near to
soil level. If left to touch the ground they may well catch soil borne diseases which then
go on to infect the whole plant.
If your bush tomatoes become too large to support themselves, either trim out a few
major branches or add more support canes - the side branches can then be
tied into the additional support canes.
Limit the number of trusses of
tomatoes to seven or eight by pinching out any surplus ones.
Upright / cordon varieties are commonly cultivated in pots, grow-bags, the
greenhouse and sometimes outdoors in open soil. When
the first fruits begin to form, the plant will produce side-shoots in between the main stem and the leaf stems.
These side shoots (see arrows in diagram on the right) should be removed by
out with the fingers. If allowed to grow they will produce a mass of
foliage but few tomatoes. Any shoots which have been overlooked and
allowed to grow should also be removed (see X in diagram). If you click
the picture on the right, a real picture will appear identifying two
side shoots on a real tomato plant.
Lower leaves which show any signs of yellowing should also be removed to avoid the risk of infection.
When the plant has developed six or seven trusses of tomatoes (normally
July time), 'stop' the plant by breaking off the growing tip. If
any more than seven trusses of tomatoes begins to develop, pinch them
out to encourage the plant to produce good quality tomatoes rather than
an abundance of low quality late-maturing fruit.
Pick as soon as the fruits are ripe (colour and size will identify this) for the best
flavour - eat as soon as possible. This also encourages the production
of more fruit. As soon as a frost threatens (around October in the UK), harvest all the fruit
immediately and ripen them on a window sill. With upright varieties, it
is possible to gently flatten the plants onto the soil and cover with
horticultural fleece to protect them from the frost.
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