Help, my tomatoes aren't turning red

It can drive you crazy. A beautiful tomato plant that you have pre-grown from seed to proud climbing plant. Every day or every few days you go and check if the plant has everything it needs. You plant your plants in fertile soil full of nutrients. After a while the yellow flowers shine in your greenhouse or conservatory , the insects that come to sit on them make you dream of delicious tomatoes. Then green balls form from the hearts of the flowers, your heart rate goes up. And the green balls become bigger and bigger and take on the shape of the eventual fruit. Your mouth is already watering and every day you go and check in the greenhouse to see if they are starting to blush but in vain ... The third, fourth or even fifth bunch of tomatoes has already formed and still no red tomatoes. You are slowly getting annoyed because you realize that something is wrong ... but what ??? You can read it in this article ' Help my tomatoes are not turning red !

Help my tomatoes are not turning red

What makes a tomato red?

The most important factor is the variety, which types do you have? Smaller varieties such as cherry tomatoes or snack tomatoes turn red faster than larger varieties such as the beef tomatoes Coeur de Boeuf . It goes without saying that 'red' is not always the right word here because there are also tomatoes that turn yellow, orange, brown or purple. By red we actually mean ripe. There are even tomatoes that stay green. By lightly pressing the tomato, you can tell if they are ripe. The type therefore largely determines how long it takes for a tomato to ripen.

Beef tomatoes ripen slower than cherry tomatoes

The green adult phase

A green mature tomato is a tomato that is ready to change color. Tomatoes cannot turn red if they are not 'green mature', not even through technology. The tomatoes only start to get color when they are green mature. The green mature growth phase is the phase at which supermarket tomatoes are picked. These then ripen during transport or in gas chambers. A tomato mainly builds up acids in its green phase. The sweet taste and aromas only come when coloring. When the tomatoes ripen in a truck or a storage room of a vegetable processing company, they will therefore not be very sweet or aromatic. If you let your tomatoes ripen on the bush, where the leaves of the plant convert the sunlight into sugars and all the aromas are formed, then you have top tomatoes. The best there are!

Green mature tomatoes already have the size and shape of the final tomato

Temperature provides lycopene and carotene for growth into mature green

A condition for growth to green mature tomatoes is temperature. Remember the tomatoes that are still green in October-November? They no longer ripen on the plant. If they are green mature, you can still ripen them indoors (where it is certainly more than 10 degrees) in a paper bag. Tomatoes produce two substances that make a tomato grow (not color), lycopene and carotene (also found in carrots). Between 10 and 29 degrees these substances ensure green mature tomatoes. Below 10 degrees your tomatoes will not grow. Above 29 degrees the process that produces lycopene and carotene is stopped.

Ripening tomatoes thanks to ethylene

Ethylene turns mature tomatoes green

Tomatoes start to color because of a chemical called ethylene, a gas. Ethylene is odorless, tasteless, and invisible to the naked eye. When the tomato is green and mature (thanks to lycopene and carotene), it produces ethylene. Supermarket tomatoes are made red in chambers that they fill with nitrogen and ethylene. But the sugars and aromas that the sun gives to the tomatoes hanging on the vine, supermarket tomatoes do not get. That is why we long for the first ripe tomato from our own garden. Maybe gardeners should have a day off from work to celebrate the day of the first ripe tomato. I vote for it!

Supermarket tomatoes are picked green and artificially ripened

Back to ethylene ... when the gas comes into contact with the tomatoes, the tomato starts to color. Persistent wind can therefore be a problem for tomatoes. The ethylene gas is blown away from the plant and slows down the ripening process. Green mature tomatoes that have fallen from the plant due to wind or frost, can be further ripened in a paper (bread) bag. The bag will retain the ethylene and your tomatoes will still ripen. If you add a banana to the bag, it will go faster, bananas give off ethylene.

Ripening tomatoes in a bag

There aren't too many things a gardener can do to speed up the ripening process. Mother Nature can't be told what to do, and she plays a huge role in the ripening process of your tomatoes.

Why are my tomatoes still green?

My plants have 3 to 5 bunches of tomatoes and only now are the first tomatoes starting to colour. With what I have learned above I can conclude the following. Since the fruiting of my tomatoes at the end of May it has been very warm in my greenhouse ( garden ), +40°C every day. As a result, little lycopene and carotene entered my tomatoes. The process towards green mature plants was slowed down. In the meantime, your plant wants to reproduce and produces more and more fruits that contain seeds. But because of the high temperatures they do not become green mature, so they do not produce ethylene to ripen. At the same time I also open the two doors and the roof windows of my greenhouse to still get the temperature down. This partly blows away the ethylene from the green mature plants. Although I think this is less of a part of the problem.

Hopefully lots of tasty tomatoes from the vegetable garden

I worry a little when I think that my plant has to give 5 bunches of aroma and colour at once. While in other years, when I planted my plants later, it was only bunch per bunch. Last year I had sown my tomatoes at the end of March and had tomatoes from the end of July to the end of October. As it looks now, I will have my first tomatoes three weeks earlier, but it will probably be 'game over' at the end of August, beginning of September. I have advanced my season by 3 weeks, but I have shortened it by 8 weeks. I also fear that my tomatoes will have less flavour because they have to produce sugars and absorb aromas in a shorter period of time. No, next year I will mix my cultivation. 1 or 2 early sown plants (beginning of March) and the rest I sow at the end of March. A little more experience every year. Finally Hopefully you have learned something from this article, I certainly have. If you find this site interesting, then definitely consider buying your vegetable garden supplies in our webshop . This makes it possible to make even more information and videos about our beloved vegetable garden. With the discount code 'biomoestuin' you will receive a 5 euro discount on your first purchase. Enjoy your vegetable garden and until the next time. Tom