Signs of overwatering tomato plants can be mild or severe, depending on the situation and length of time during which too much water was present around the tomato roots. Mind you, overwatering is not always due to irrigating with too much water.

Signs of Overwatering Tomato Plants

It is sometimes due to neglecting issues such as enhancing good drainage and adjusting to seasonal changes. The focus of this article is on highlighting the signs that your tomato plants are being overwatered.

A List of Sure Signs of Overwatering Tomato Plants

The signs of overwatering tomato plants range from yellowing leaves to rotten roots. We always recommend that you put in place strategies that prevent overwatering, and these include checking the soil before giving your tomato plant a drink. However, if your tomato plants become overwatered by any chance, knowing the possible signs will aid in the diagnosis, which will help you to take appropriate action. 

In this section, we’ll look at the red flags to be on the lookout for, as well as the possible causes and necessary action, in addition to a bonus of further care nuggets that will ensure that your tomato plants grow healthy.

1. Root Rot 

Root Rot

  • Roots appear mushy and brown, as compared to the white ones that are healthy
  • The rooting system becomes smelly
  • Roots can be slippery upon touching them
Possible causes
  • Too frequent watering that caused the plant to sit in soggy soils for extended periods of time
  • Using the same watering frequency when temperatures or seasons change
  • Irrigating the plant without checking the soil moisture
Appropriate action
  • Gently uproot your plant to assess the extent of the effects caused by root rot.
  • If the situation is not that severe, trim off damaged roots, treat with a fungicide, dip in a rooting hormone, and repot the plant.
  • If the rooting system is severely damaged, you can use the healthy parts of the overwatered tomato plant for propagation and discard the diseased ones
Further care nuggets
  • Once repotted or propagated, ensure that your tomato plants get about two inches of water per week
  • Water only when one inch of the topsoil is dry
  • Use a toothpick or chopstick to assess if your plant’s soil is dry before you water tomato plants

Root rot is caused by fungi that thrive in waterlogged conditions, where aeration and drainage are poor. This infection will cause the roots of your plant to start rotting, thereby reducing their ability to take up nutrients from the soil to other parts of the plant. 

Moreover, soggy conditions are characterized by clogged air spaces, so your plant won’t be able to breathe, thereby further promoting the development of root rot. Please, remember to wear gloves as you handle your plant with root rot.

2. Wilting and Yellowing Foliage

Wilting and Yellowing Foliage

  • Yellow leaves and stems
  • Weak, shrunken, or wrinkled leaves and stems
Possible causes
  • Severe root rot
  • Root damage to the extent that they can’t supply the foliage with nutrients and water
  • Lack of balance between the number of healthy roots and the foliage
Appropriate action
  • Check your tomato plant for root rot
  • Remove affected roots and treat the remaining ones with a fungicide
  • Discard the plant if most or all its leaves have been severely affected
Further care nuggets
  • If only a few tomato leaves have been affected, repotting the plant may help
  • If you discard the tomato, be sure to disinfect the space where it was to protect other plants from being infected
  • Remember to discard the potting soil as well


The leaves of your tomato plants depend on the roots for their nutrient and water supply. If the roots are severely damaged or affected by root rot, their ability to provide resources to the rest of the plant becomes compromised. This lack of resources that are relevant for growth and survival results in the leaves turning yellow. Such yellow leaves cannot make plant food through the process of photosynthesis.

3. Stunted Growth

Stunted Growth

  • Growth of the plant slows down
  • Leaves are smaller, and so are the fruits
Possible causes
  • Poor draining soils
  • If you are growing the tomatoes in pots, the drainage holes may be too few or clogged with soil particles
  • Damaged roots
Appropriate action
  • Use soils that are nutrient-rich, with a free-draining capacity, though they should be able to retain some moisture
  • If drainage holes of the pot are blocked by soil particles, unclog them using a toothpick or a similar tool
  • Replant the tomato in a pot that has more drainage holes
Further care nuggets
  • Some soils become more compacted as time progresses, so always loosen them using a garden fork
  • Adding perlite or a little sand to your soil may increase its drainage capacity

As long as the aerial parts of your tomato plant do not receive enough nutrients and water, they are unable to make adequate food that aids the optimum growth of the plant. This is the stunted growth scenario that happens when tomato roots are sitting in water. The rate at which the tomato plant leaves grow matches the support that they have from the roots. The greater the support, the faster the growth rate, and the bigger the foliage and fruits produced.

4. Cracked Fruits

Cracked Fruits

  • Tomato fruits become cracked at the bottom
  • Fruits become too watery that they lose their flavor to some extent
  • Fruits become overly turgid
Possible causes
  • Pest control strategies that add more water to the plant soil
  • Using liquid fertilizers during a session that is separate from the watering one
Appropriate action
  • Pest control methods that involve water should be counted as a separate watering session
  • Merge your watering and fertilizing schedules so that you do both in one session
  • Reduce watering to let your plants recover
Further care nuggets
  • Consider using pest control methods like Neem oil, which do not add much water to the plant soil
  • You can also use solid, slow-release fertilizers instead of liquid ones that you might need to add more frequently

When your tomato plant is overwatered, and the roots are still healthy enough to take up the water, the foliage and fruits become overfed. The cracked fruit is a sign that there is too much water available than what is necessary. As a result, the fruit slightly bursts in a bid to relieve itself from the pressure of harboring excessive water.

5. Blisters on Leaves

Blisters on Leaves

  • Leaves have bumps or water blisters
  • The water bumps may turn corky if overwatering continues
Possible causes
  • Too high humidity levels
  • Using soils with too much water-holding capacity
  • Too frequent watering
Appropriate action
  • Cut down on watering
  • Remove any humidity-enhancing tool, such as the pebble tray to lower humidity levels
  • Ensure that the soil and pot have good drainage capacity
Further care nuggets
  • Never water tomato plants when the soil feels wet
  • Ensure that your plant grows under humidity levels between 65 and 85 percent
  • Well-draining soils that are not compared are ideal

When humidity levels are high, levels of transpiration and evaporation also reduce. This is because these processes follow the rule of flowing from a region of high concentration to that of a lower one. 

So, if the atmosphere is saturated with moisture, the plant and soil can’t release more. This is why it is also important to adopt the habit of watering tomato plants when the topsoil is dry.


Overwatered tomato plants can easily be noted through various signs, some of which we have highlighted in this article.

Let’s quickly have a recap of some of the ideas that we discussed:

  • Root rot is the most severe sign of overwatering.
  • More signs of overwatering include wilting and yellowing foliage, cracked fruits and blisters on the leaves.
  • Some of the common remedies for overwatered tomatoes are reducing the watering frequency, using less aqueous methods of pest control, and improving the drainage system.

With the information that you learned from this article, you will become more confident in dealing with overwatering when you plant tomatoes. Apply the knowledge and enjoy your gardening experience!


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