Green shoulders around tomatoes: A physiological disorder that can be avoided

Do you grow plenty of tomatoes in your garden? If you do, you probably make ketchup, dry them, or process them in many other ways. When you harvest tomatoes, you will certainly have fruits that are coloured as they should be. But you may also find that many of your tomatoes are always green or yellow around the stem. It may seem that they simply “ran out” of red colour. It is a pity, because this part of the fruit will certainly not be as sweet as the rest of it. How is this disorder characterized, why does it occur, and can it be avoided?

A Physiological Disorder

Tomatoes sometimes do not colour evenly. The flesh is not ripe and relatively hard around the green or yellow spot. This is a physiological disorder, which is referred to as green or yellow shoulder or sometimes as a green or yellow hood. Well, if you look at a tomato which is green around the stem, it kind of resembles a hood or shoulder. This problem often appears in greenhouse and less in tomatoes grown outside. You will often found it on large fleshy tomatoes.

Photo: Radek Štěpán

What is Causing this Problem?

Most often these problems are caused by a lack of boron and potassium or by too much of nitrogen, and surprisingly, sunlight also promotes the occurrence of this disorder. Most often you will see green shoulders on fruits exposed to direct sunlight. Fruits on the top and also tomatoes growing at the edge of your veggie bed are the spots where the sun roasts them the most. And to include everything, also fruits infected with the mosaic virus show similar signs.

Photo: Radek Štěpán

You May Be Able to Avoid It

Well, if you see a piece of green colour on the fruit during the main harvest season, it will most likely not bother you and you may just cut the green part out. You will not lose much flesh anyway. There is not much you can do if your tomatoes ripen on your veggie bed. But if you can let your tomatoes ripen in the dark at the end of the season, they will gradually colour more evenly.

Photo: Radek Štěpán