You have beautiful plants, full of fruit, but the tomatoes stay green for a long time…
Does it take a very long time for them to ripen?
Let’s start by putting aside our impatience as gardeners…
A tomato does not ripen overnight.
It takes several weeks from formation (variable according to variety and growing conditions) to reach maturity.
It is normal.
But when they reach their optimal size (they stop growing), they should start to change color quickly…
They should…
But sometimes tomatoes remain hopelessly green.
They take a very long time to mature… or even fail!
Let’s try to see the possible causes and fix them.
Tomatoes stay green or ripen badly during heat waves…
The idea for this article about ripening tomatoes came to me last year.
At home I have noticed for a number of years in a row that tomatoes remain green longer during intense heat waves (of course we exclude types of green tomatoes, such as Green Zebra…) that ripen for a long time.
With practically a whole month (July) with exceptionally high temperatures (40°C and more at home…), this slowdown was even more pronounced last year.
These heat waves, with significant consequences for the crops (especially the very high temperatures can completely interrupt the flowering… ), are becoming more and more intense and long almost everywhere.
So maybe you have also noticed that your tomatoes ripen harder? And you wondered why?
Search no more…
It is the high temperature that is the cause.
From 30°C (we’re talking tomatoes here, and this temperature data is a bit arbitrary – just to give you an idea), the leaves curl up, reducing the surface area available for photosynthesis, resulting in a slowdown of the juice circulation in the plant.
The elements involved in the ripening process (especially phosphorus, but also potassium, calcium or magnesium, etc.) then reach the fruit more slowly and in smaller quantities.
As a result, the ripening process is already considerably slowed down…
Above 35°C, the juice circulation is practically stopped, depriving the fruits of the elements essential for their ripening … which is simply stopped … at least during the warm hours of the day.
Because the process can be resumed during cooler hours…
But it is clear that the daily ripening times of suitable temperatures (i.e. lower than mentioned above) are shorter… and therefore the tomatoes take longer to ripen.
We must also try to adapt our gardening to these increasingly frequent and intense heat waves…
Personally, I sow fairly early in order to be able to plant part of the tomatoes from April (but watch out for frost)… it will be missed: big heat wave in June! Another good reason to spread your harvest).
I am also thinking and testing the shade to soften the temperatures a bit at the level of the tomato plants… but it really should not be very dense, and not too long during the day, otherwise it lacks light , flowering is poor and the tomatoes don’t even form…as we’ll see below).
Please note that not pruning tomatoes, as has been practiced by the undersigned for years (or not practiced…that is up to you) will not have a positive influence on the question that concerns us today. Certainly, the fruits that are inside or at the back (relative to the sun) of the bush thus formed will benefit from a certain shade (and will be protected from possible sunburn… which in itself is a can be a good thing). But the foliage, through which photosynthesis takes place, and thus the sap circulation, remains just as exposed to heat…
If there is insufficient sunlight, tomatoes remain green or ripen badly
Insufficient sunlight can also be the cause if tomatoes remain green or ripen very slowly.
Bad weather delays the ripening of tomatoes
The weather can sometimes be responsible for this (cloudy and/or rainy days)… Then there is nothing to do but wait for it to get better.
Or your tomato plants are in a place that is too shady, with insufficient daylight…
For example, most of the day (all afternoon) I have a small shaded spot close to home.
Every year, looking for a solution to the problems surrounding heat waves, I do a few tests there…
But the tomatoes I plant there, as long as they manage to form (there is little bloom, and the few flowers fall off) remain green indefinitely… they don’t ripen…
Even cherry tomatoes (too bad… handy to have on hand for an aperitif)…
The reason is simple: plants are not exposed to sunlight to produce and ripen properly.
In short, for me, but also for you if your tomato plants are in a similar situation, I think there is a balance to be found between too much sun and too little light…
Ideally, they should be shaded only during the hottest hours of the day…
What can be achieved with a shade net (or an openwork trellis) high above the crops (we recommend 50% shade nets in warm areas and preferably 20% in less warm areas); something I haven’t done yet, but am seriously considering…
Ripen on unpruned tomato plants
If your growing conditions are not conducive to this method of not pruning tomatoes (bad sunshine), the lack of sunlight exposure will also make it difficult to ripen the fruits (tomatoes will remain green again).
As I mentioned in the article about not pruning tomatoes, it may be wise to do some testing…
If you have pruned plants and unpruned plants, you can compare the 2 methods.
And since every year is different, you will find that some years the unpruned plants will be more productive than the pruned ones, and vice versa in other years…
In other words, applying these 2 approaches together will ensure consistent production every year.
Soil shortages and ripening of tomatoes
Another reason tomatoes stay green, or at least ripen very slowly, is a soil deficiency (or clogging), especially in phosphorus, but also in potash or calcium.
A preparation based on comfrey root, due to the content of this plant in these various mineral elements, can quickly compensate for these deficiencies, whether they are related to a real deficiency in the soil or to a blockage.
But then the effect is only temporary…
By striving for a living and fertile soil (a focal point of Mon Potager au Naturel), with appropriate and balanced contributions of organic matter, your crops will each year have the elements necessary for their growth and proper fruiting. .
Do your tomatoes stay green and ripen very slowly or not at all?
Your comments are welcome in the comments section below.
