My Tomatoes Are Wilting & Rotting – Here’s Why?

The tomato is one of the most important fruits to our diet. It provides us with a good amount of vitamins, minerals, antioxidants and fiber. But what about when it’s rotting on the vine?

You may think that it’s just a bad season for tomatoes, but the truth is that it could be a bigger problem than you think.

Check Your Tomatoes Plants for Early Blight

Early blight on tomatoes can often be found on plants that have just been transplanted. It can be easily identified because the stem will wilt and the tomato plant will appear sick.

The dark spots can be seen on the lower leaf surface and the fruit. The fungus Alternaria solani causes this disease.

Spot outbreaks can appear on the younger leaves of a plant or fruit. The disease is more severe at warmer temperatures and under humid conditions. Plants can be damaged, and produce may be reduced or destroyed.

To help prevent tomato wilt, remove any dead or infected leaves as soon as you notice them. Copper fungicides can also be applied in order to control the disease.

Key Points:

  • It is important to get the early blight early so that you can stop it before it spreads
  • Tomatoes do not tolerate freezing temperatures, so it is important to protect them
  • Tomatoes should not be planted in soil that is wet, as it will make the roots rot and the plant will die
  • The first symptom of early blight is wilting of the stems and leaves
  • Copper fungicides are available from your local garden centre

Look for Late Blight on Your Tomatoes

Phytophthora infestans is the fungus which is responsible for late blight, a disease which affects crops like potatoes and tomatoes.

 Late blight has caused devastation to Irish farmers in the past and it’s the number one cause of potato loss.

In the wild, late blight is usually transmitted by a type of leafhopper called the potato psyllid. It lays eggs on the undersides of leaves of infected plants, and these eggs hatch into first-instar larvae.

The larvae feed on the leaves, which weaken the plants. When the plants become stressed, the disease symptoms appear.

The disease is easily spread by insects and by soil-dwelling fungi that are part of a larger group of microbes known as oomycetes.

These microorganisms enter tomato plants through roots, leaves, and stems as well as through contaminated water or fertilizers.

Once they infect the plant they cause the leaves to turn yellow.

Key Points:

  • The main symptoms of this disease are wilting leaves, darkening of the leaves and, eventually, death of the plant.
  • There are many different ways that you can prevent this disease from spreading to your plants.
  • Once you have the disease, you need to treat it as soon as possible.

Consider Fusarium Wilt

Fusarium wilt is a fungal disease that causes plant decline and death in the root, stem, and leaves of tomato plants. It is known to cause wilting and yellowing of the foliage.

Wilting may spread to the whole plant even if there is enough water and nutrients available in the soil. This is a common problem with most plants in the warmer regions of the world.

If you solarize the soil, you may be able to remove the fusarium wilt fungus from the soil.

Solarization raises the temperature in the soil. If you know that your soil harbors the fusarium fungus, you should grow tomato varieties resistant to it. The tomato plants are marked with a “F” on the label.

Key Points:

  • Solarizing the soil is very effective against fusarium wilt
  • Some varieties have resistance to fusarium wilt
  • It is important to grow resistant varieties if you suspect your soil harbors fusarium wilt fungus

Check Your Tomatoe Plants for Blossom End Rot

Blossom end rot is a common condition for tomatoes. Often, the problem starts as a small, red, discolored spot on the blossom end of a tomato.

As the spot progresses, the fruit turns a more severe, brownish color. Once the rot has started, it is almost impossible to stop.

Blossom end rot (BER) is one of the most common types of fruit rot, but its cause is often attributed to an infection of a pathogen.

Tomatoes grown in sandy soils are more likely to be affected by blossom end rot. The cause of blossom end rot won’t be cured with a pesticide.

 To prevent blossom end rot from infecting your tomatoes, check the soil moisture of your planted tomatoes and water them when the soil gets too dry, but do not overwater.

Adding tomato fertilizer to your garden will not only add nutrition to your tomatoes, it will keep them vigorous and free of nutritional deficiencies.

Key Points:

  • Blossom end rot can be prevented with good soil care
  • Tomatoes are more likely to be infected if the soil is dry
  • You can prevent blossom end rot by watering tomatoes frequently

Preventing blossom-end rot

To grow tomatoes, start your plants indoors under lights and then transplant them to the garden. Apply fertilizer according to the soil test results.

  Use fertilizers low in nitrogen, but high in phosphorus, with numbers similar to 4-12-4 or 5-20-5. This will reduce the chances of blossom-end rot.

After fruits set, weed thoroughly and water deeply. That’s one of the things we do for our tomato plants – use a deep watering system in the pot and apply some compost fertilizer around the plants.

Maintain a consistent supply of soil moisture. Tomato plants require adequate amounts of water to grow properly. It’s important to keep them well hydrated by irrigating with a soaker hose when you have the opportunity.

This type of watering is preferable to overhead irrigation in the home garden.

Mulching your tomatoes is one of the best ways to conserve water and nutrients in your soil.

In fact, mulching with organic materials is a good way to prevent weeds and keep the soil fertile.

This rot doesn’t spread from plant to plant, or from fruit to fruit, so even if it occurs on your earliest tomatoes, it may not affect later tomatoes on the same plant.

For a particular disease, we need to consider whether a fungicide, insecticide or all three together is the best combination of prevention and cure.

Key Points:

  • Preventing blossom-end rot is more important than curing it
  • Water deeply and use a deep watering system
  • Mulch your tomatoes to conserve water and nutrients in your soil

Frequently asked questions

Q: How do I know if my tomatoes are blighted?

A: Look at the stems of your tomato plants. If they look wilted, then they probably have been blighted.

Q: Why are my tomatoes going soft on the vine?

A: The most likely causes of your leaf chlorosis are too much nitrogen and not enough potassium. Nitrogen should be in the range of 4 to 5.

Q: Why are my Tomatoes rotting after picking?

A: Blotchy ripening, also known as whitewall, occurs when fruits have a variety of colors, from white to green, red, orange, or pink.

It happens when the fruit is exposed to excess heat, which can cause internal sugars and acids to break down, resulting in a whitish or yellowish color.