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It’s very disappointing to find out that your tomatoes are rotting while they are still on the plant. Nobody wants to have to throw away long-awaited tomatoes.
Why does this happen? Why do tomatoes rot on the vine?
Several things could be causing this to happen. Unfortunately, you have no way of predicting this condition until it shows up.
We have outlined the reasons for tomato rot in this article and also provided solutions that will prevent this from occurring next time.
Why Do Tomatoes Rot on the Vine?
Tomato rot typically manifests as sunken, black, wrinkly areas on a tomato. The most common form of tomato rot is Blossom End Rot (BER).
With blossom end rot, tomatoes begin to decompose opposite where the stalk is attached to the fruit and where the flower was once attached.
This is where blossom end rot starts. This end of the tomato will begin to change color at some point in its development and eventually decay.
Sadly, blossom end rot often strikes your tomatoes weeks or even days before the harvest. So what’s the culprit?
There are 4 preventable reasons for tomatoes rotting on the vine:
1. Overwatering or too much moisture
When tomato plants absorb too much water at a fast pace, the tomato skins break and rot sets in. Too much water can be by artificial or natural means.
Artificially, if you hand water your tomato plant too often without allowing the soil to dry in between watering, your tomato may begin to rot. On the other hand, if the tomato plant receives too much rainfall and not enough sunlight, expect the same results.
Another way this could happen is if you plant your tomato in full shade. Tomatoes need to be planted in full sun so that the water content in the soil can evaporate fast and the roots will be saved.
Other signs of overwatered tomatoes are yellow leaves, cracks on the fruit, watery taste and mushy texture.
To prevent overwatering, give your tomato plant no more than 5cm of water every week. For potted tomatoes, use high-quality soil that drains well and sun them.
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2. Lack of calcium in the soil
Poor quality soil lacking in important nutrients is another reason why tomatoes rot on the vine. Tomatoes depend heavily on calcium to flourish.
When it is lacking in the soil, the tomato plant responds by displaying rotting fruit.
3. Using the wrong fertilizer
Using fertilizers with high nitrogen content diminishes the calcium in the soil, resulting in tomatoes rotting on the vine.
Instead of nitrogen-rich fertilizer, use one with high phosphorus and low nitrogen. It should be in the ratio of 2:1. Better still, consider replacing fertilizer with a more natural nutrient source, like compost.
In addition to using the wrong fertilizer, if you fertilize too early on in your plant’s life, the plant will grow bushy fast but it will compensate for this rapid growth by producing tomatoes with rot.
It is not a good idea to force tomato production.
4. Damage to tomato plant roots
Tomato plants have one of the most sensitive root systems around. If there is any little disruption, it will show in the overall health of the plant.
Damage can occur, for example, during rough weeding. When rots of nearby plants get tangled together and you tug on them aggressively, you can accidentally damage the roots.
Damaged tomato roots will struggle to take in nutrients and the tomato plant will suffer. To prevent weed growth around tomato plants, apply a layer of mulch around them.
This way, you will reduce the likelihood of having to pull up weeds. An added advantage is the moisture retention that mulching offers.
How Do You Keep Tomatoes From Rotting on The Vine?
It is nearly impossible to save tomatoes that have already begun to rot on the vine, but we can try. We can also use these remedies to make sure that tomato rot doesn’t happen again.
1. Measure water intake for tomato plants
As earlier stated, provide just 5cm of water for your tomato plants every week. Most plants don’t like their “feet” wet for extended periods and will not appreciate excessive moisture.
Tomatoes are not an exception. For fresh, firm tomatoes during harvest, let the soil have enough time to dry before you water it again.
Let your tomato plants receive full sun for 6 to 8 hours every day.
If you’re not sure if your tomato plant needs water or not, stick your finger an inch or two into the soil to check for dryness then act accordingly.
2. Mulching and careful weed control
Mulching soil can eliminate the need to remove weeds near your tomato plants. Weed roots tangling with your tomato roots spell disaster for them.
It will be very difficult to separate weed roots from tomato roots without causing some form of damage.
Mulching the soil will also allow it to dry out evenly.
3. Don’t fertilize tomato plants too early
Wait till 3 weeks after planting your tomato to give the first application of fertilizer. While you do that, make sure it is a fertilizer that has more phosphorus or calcium content than nitrogen.
Forcing your tomato plants to put out fruits prematurely will lead to tomatoes rotting on the vine eventually.
4. Use good-quality planting soil
The quality of soil you use to plant your tomato will greatly affect the kind of tomatoes they will produce.
Use soil that doesn’t retain water and has all the necessary nutrients. Of these, calcium is the most important for good tomatoes.
If you find out that the soil is deficient in calcium, you can boost its levels through these natural ways: using crushed egg shells and shell meals (which can be bought from the local store).
Put the crushed eggshell powder 6 or 7 inches below the soil, as close as possible to the tomato seed or root. You can follow the same process for the shell meal.
Gypsum or calcium sulphate is another natural calcium source. When using gypsum, make sure to water it well.
Lastly, to prevent tomatoes from rotting on the vine, the soil pH should be between 6.5 to 6.8. Keep the soil pH within this range for the firm tomatoes.
We hope that by now you have learnt 4 different reasons why tomatoes rot on the vine. You can see that they are all preventable through proper care of your plant.
You have also seen measures to take to prevent tomato rot from happening again.
Tomatoes are picky plants when it comes to things like water needs and nutrition, but they will do well if all the guidelines are followed strictly.
We wish you the best harvest of firm, juicy, rot-free tomatoes next time!