How Do You Keep Tomato Plants From Growing Too Tall?

In tomatoes, different varieties are distinguished according to their growth – on the one hand, there are the rod tomatoes, which can grow indefinitely in height, and on the other hand, there are bush tomatoes, which form many branched side shoots. Mini tomatoes grow very stout and hardly grow in height.

Many bush tomatoes reach a maximum height of about 1.50m. The plant bears its fruit on the numerous side and axillary shoots. Bush tomatoes do not need to be thinned out and, as a rule, do not need to be shortened.

Tomatoes grow too high – shorten main shoot

Tomatenpflanzen im Gewächshaus

The situation is different with stake tomatoes. They have a main shoot that grows upwards and from which branches form to the side, from which the fruits later hang. With stake tomatoes, it is advisable to let the main shoot grow to a desired height, and then shorten it when two or three strong side shoots have formed at the top. Then you can cut the main shoot, ensuring that all the strength and nutrients of the plant go into the existing branches.

It is also often recommended for pole tomatoes to leave only 4-6 side branches along the main shoot, and to cut all the others. In this way, fruiting is concentrated specifically on these branches and a higher yield, as well as uniformly ripening fruits are the positive result.

Tip: Axillary shoots should also be pruned out from pole tomatoes, they also take too much energy from the plant, which should better flow into the main branches and thus into the fruit. Very important with stake tomatoes: Attach the plant sufficiently (tomato branch, trellis, fence, rod, stick, etc.)! Once a few grams of fruit hang on the shoots, they can easily snap off if they are not sufficiently secured.

Balanced growth of tomato plants is certainly desirable for any amateur gardener. However, if the plants shoot up too quickly, this is referred to as “yellowing”. This sometimes has fatal consequences for the health of the plants and should therefore be recognized in good time and at best avoided.

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Shorten tomato plants

Some tomato varieties have unlimited growth and can reach a proud height of up to two meters. These include, in particular, the stake tomatoes, whose main shoot grows incessantly. But even with this variety, too high growth is usually not desirable. Because, on the one hand, there is often not enough space, and on the other hand, too pronounced growth can be detrimental to the harvest. Therefore, it is advisable to shorten the stick tomatoes from a certain height as follows:

  • after the fourth or fifth inflorescence
  • as soon as 2 to 3 strong side shoots have formed
  • carefully cut the main shoot
  • or leave several side shoots
  • and cut off all others

Tomatoes become yellow: Cause and consequences

The so-called horny growth is an unnatural growth in length, which often occurs in seedlings. This is the case when the relationship between temperature and light is imbalanced. To compensate for the light deficit, the tomato plants grow accordingly quickly upwards to be closer to the sun and thus to be able to grab more light. In doing so, the plants put all their energy into growing upwards at the expense of their own health:

  • the plants form weak, thin shoots
  • the formed shoots are not stable
  • the plant does not form thick stems
  • this could cause it to break
  • the tissue is also weak
  • this makes them more susceptible to pests and bacteria
  • the root growth is absent
  • thus it can starve

Caution: But it is not always the lack of light that triggers the rotting, because an over-supply of nitrogen can also be responsible for this unnatural growth in length. However, nitrogen is easily soluble and can be simply “washed” out of the soil. A preventive measure is mulching with straw, because this attracts the nitrogen to itself.

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Wilted seedlings – what to do?

In the case of tender seedlings, special care must be taken to ensure that they are given the optimum conditions for growth. Because if they start to become yellow, there is a risk that they will not develop sufficiently and will only have poorly developed firming tissue. Therefore, it is advisable to always monitor the seedlings to allow early detection of horny growth. If unnatural length growth is evident in the seedlings, it is best to proceed as follows:

  • Place seedlings deeper into the soil
  • this will stabilize the bend
  • new root mass is also formed
  • place the plants in a cooler place
  • Preventing horny growth in tomatoes

Tomato plants can be prevented from becoming yellow by creating optimal conditions for the plants. To do this, it is essential to know the specific needs of the plants. In addition, for example, the use of an indoor greenhouse, which provides sufficient light and heat. The optimal conditions for healthy growth are given when the following requirements are met:

  • sunny location, about 6-8 hours of light per day.
  • ideal temperature for seedlings is 20-24 °C
  • after germination slightly cooler, ideal is about 18 °C
  • in the greenhouse maximum 30 °C

Tomatoes die – what to do?

It is not always possible to create the optimal conditions, which is why the occurrence of yellowing is sometimes unavoidable. As soon as the plants become yellow, the first thing to do is to find out what is causing it. Then it is necessary to act quickly, because with these simple steps, the plants can be saved:

Reduce temperature

Tomato plants are heat and sun lovers, so they react accordingly to these conditions. Basically, the warmer it is, the more light the plants expect. However, if this ratio is imbalanced, the plants will sprout. If the sprouting has already occurred, lowering the temperature can counteract it. For this has the following effects:

  • the plant’s metabolism slows down
  • it does not become yellow as quickly
  • in addition, the plant does not hope for so much light
  • and does not grow further in the height
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Provide more light

Especially in the dark months, as well as when trying to overwinter the tomato plants, it is essential that sufficient light is provided. If there is a lack of sunlight, it is therefore advisable to compensate for the lack of light with artificial lighting. Special plant lamps are available for this purpose, but commercially available energy-saving lamps or fluorescent tubes are also suitable. It is important that the light sources have the following characteristics:

  • they should be adapted to the color spectrum of the plants
  • the light should fall in the red as well as in the blue spectral range
  • the lamps should not get too hot
  • otherwise the plants can burn
  • the light spectrum should be sufficient

Do not use fertilizer

Tomatoes are highly nutritious and enjoy a balanced fertilization. However, the supply of nutrients is counterproductive for yellowing plants, as this has the following effects:

  • by fertilizing the plant receives more nutrients
  • and thus more energy
  • and can accordingly grow faster upwards


  • James Jones

    Meet James Jones, a passionate gardening writer whose words bloom with the wisdom of an experienced horticulturist. With a deep-rooted love for all things green, James has dedicated his life to sharing the art and science of gardening with the world. James's words have found their way into countless publications, and his gardening insights have inspired a new generation of green thumbs. His commitment to sustainability and environmental stewardship shines through in every article he crafts.

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