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My tomatoes do not turn red! Why and what can I do if they remain yellow or turn brown?

They are part of the menu all year round, but in the summer they taste best. But those who have grown tomatoes in their own garden or on the balcony, know the problem – sometimes they just do not ripen, but remain small and yellow. And sometimes they even turn brown. Your tomatoes do not turn red? What could be the reason and what you can do about it, we tell you in the article.

Why don’t my tomatoes turn red? This could be the reason!

Tomatoes do not turn red as let ripen

When the tomatoes bear fruit abundantly, the amateur gardener rejoices and can hardly wait for harvest time. The ripening period lasts between 14 and 21 days. During this time, the fruits gradually turn red. The taste also changes: the ripe tomatoes are aromatic and sweet. In order for them to be ready for harvest around the end of July – beginning of August, the phytohormone ethylene plays a crucial role. The plants produce ethylene themselves, but need sufficient heat for this. At the same time, the weather should not be too hot.

Getting green tomatoes to ripen

cut off leaves and new shoots to shorten ripening time of tomatoes

  1. Temperatures too low: Green tomatoes, for example, will not turn red and ripen for harvest if temperatures exceed the 30-degree mark or fall below 10 degrees Celsius in late summer and fall. Possible solution: Move tomatoes into the greenhouse or transplant in late summer.
  2. Too long growing season: In addition, tomato plants tend to invest a lot of energy in leaf formation. Cut only the lower shoots growing close to the ground to encourage fruiting.

Allow tomatoes to ripen on the bush

  • Cut off the new leaves at the end of the season. Leaf formation uses too much energy, which the plants desperately need for fruit.
  • Cut off fruits that are too small. Early to mid-August is already too late to form new fruit. It is best to remove all small tomatoes so that the others can ripen.

remove small tomatoes in autumn and let them ripen

  • When temperatures are high, either move the tomatoes to a shady location (if they are grown as potted plants) or shade the plants.
  • When temperatures are low, move the plants to the greenhouse and place ripe bananas near the tomatoes. The bananas will produce and release ethylene. The hormone will significantly shorten the ripening time of the tomatoes on the bush.
  • Pick the ripe fruit regularly.
  • Varieties that bear small tomatoes, such as cherry tomatoes, will ripen much faster than varieties with large fruits, such as oxheart tomatoes.

How do tomatoes turn red faster?

Especially at the beginning of autumn, when the weather becomes colder and tomatoes do not get enough heat, the next trick can shorten the ripening time. Adjust the watering. In drought conditions, plants put all their strength and energy into the fruit. They do not form new leaves and do not grow further .

You can also cut off the shoots with green tomatoes and hang them upside down in a sunny place. However, the fruits should have reached a certain size and at least partially red.

Why tomatoes do not turn red at the top, but brown: blight.

green tomatoes attacked by fungal disease


Tomatoes often fall victim to blight. The first signs of the fungal disease – small brown spots on the leaves and shoots – often go unnoticed until it is too late. The fruits do not turn red on top, but brown and are then no longer edible. Possible care measures are: Sprinkle the plants with rock flour and immediately cut off the diseased shoots, fruits and leaves. The infested plant parts should then be disposed of with household waste and under no circumstances composted or used as mulch in the garden. The healthy fruits should be harvested as soon as possible, even if they are not yet ripe.

Installing a rain shelter may also prove helpful. Also, be careful not to wash soil onto the lower leaves when watering. You can transplant potted plants. If the disease is particularly bad, you can use fungicides. When doing so, always get information at the garden center before buying and treat the plants alternately with different fungicides.

Tomatoes remain yellow: green collar

Unlike both blight, green collar is not a disease, but a condition promoted by improper care, location and excessive temperatures. The signs of green collar are green rings around the base of the stem. The fruits cannot ripen but remain hard and the flesh has no flavor. They are still edible as long as you cut off the green areas.

Why do the balcony tomatoes not turn red?

cut off tomatoes including stem and let them ripen upside down

There are many possible reasons why balcony tomatoes do not turn red. Most often it is not due to disease or pests, but a lack of nutrients. Therefore, the potted plants need regular fertilizing. In addition to various organic fertilizers from the garden center, several types of clover are also suitable for green manuring.