10 Tomato Seedling Problems and How to Protect Them?


Lack of nutrients can cause seedling problems. Tomato seedlings from seed can be a fun and rewarding project. But, like all gardening projects, it doesn’t always go as planned.

When growing tomatoes from seedlings, there are many things that can go wrong, from seedlings that grow too tall to diseases caused by fungi.

In this article, we will discuss 10 common tomato seedling problems and provide tips on how to fix them. Whether you’re a seasoned gardener or a beginner, these tips will help you get the most out of your tomato plants.

Read on to learn more!

Tomato seeds are growing

10 Problems of Tomato Seedlings and Their Fixation

If you’re a gardener, chances are you’ve had your fair share of tomato seedling problems. yellow leaves or leggy plants, for example. There are a number of things that can go wrong when growing tomatoes from seed.

But don’t despair! By understanding these common tomato seedling problems and their fixes, or with a little patience and care, you’ll be on your way to a successful tomato harvest in no time.

In the troubleshooting sections below, I’ll go into details about the causes and fixations, and I’ll give you tons of help with tomato seedlings.

1. Leggy or Weak Tomato Seedlings

If your tomato seedlings are leggy, it’s likely that they’re not getting enough light. Tomato plants need at least 8 hours of direct sunlight per day, so if your seedlings are in a shady spot, they’ll start to stretch out in search of sunlight.


To fix this problem, move your seedlings to a sunny spot and make sure they get at least 8 hours of direct sunlight per day. If possible, give them 12 hours of sunlight per day. You can also try using grow lights to supplement the natural sunlight.

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2. Tomato Seedlings are Turning Yellow

If your tomato seedlings are turning yellow, it could be a sign of nutrient deficiency. The three main nutrients that tomatoes need are; Potassium, phosphorus, and nitrogen. A lack of any of these nutrients can cause leaf yellowing. 


To fix this problem, you have to follow some steps;

  • Make sure the soil is moist but not waterlogged, and allow the soil to dry out slightly before watering again.
  • Consider fertilizing the seedlings with a balanced fertilizer or adding compost to the soil.
  • Pests such as aphids, spider mites, or whiteflies can cause yellowing of leaves. Check the seedlings for any signs of infestation and treat with an appropriate pesticide if necessary.

3. Wilting and Drooping of Tomato Seedlings

If your tomato seedlings are wilting and drooping, it can be caused by overwatering, underwatering, or root damage. It could also be that they are not getting enough light or that the temperature is too cold or hot. 

Overwatering can cause the roots to rot, which prevents the plant from taking up water and nutrients.


  • Check the soil moisture levels and adjust watering as necessary. If the soil is waterlogged, improve drainage or repot the seedlings into fresh soil.
  • Let the soil dry out completely before watering again. You can also try to improve drainage by adding sand or perlite to the potting mix.
  • Fertilise with a balanced fertiliser and adjust watering as necessary.
  • Add coffee powder to soil because it nourishes the soil. 
  • Epsom salt is also beneficial with attacking the weed. 

4. Purple Tomato Seedlings 

Healthy plants are rich in green. Purple tomato seedlings are a common cause, and they could be a sign of nutrient deficiency.

There is no need to worry because having a purple tinge to the stems and veins of tomato seedlings is normal. Moreover, it stalled with the growth of tomato plants.


You can add some bone meals and fertilizers while transplanting. because they are rich in phosphorus, which triggers the growth of tomato seedlings.

5. White Leaves or Spots on Tomato Plants

White spots on tomato seedlings can be caused by sunscald and fungal or bacterial diseases. Sunscald happens when seedlings are in direct sunlight for too long, especially when the weather is hot. 

The intense heat from the sun can cause damage to the plant’s leaves, resulting in white spots and sometimes even blisters.


  • If your seedlings are in direct sunlight, move them to a shadier location, such as under a tree or a shade cloth.
  • If you suspect a fungal or bacterial disease is causing the white spots, you can treat your tomato seedlings with a fungicide or bactericide.
  • Sticky traps around seedlings are being used that can seize the insects and flies hovering over. And it creates shields to prevent damage.
  • To prevent sunscald, provide shade during the hottest part of the day or move the seedlings to a cooler location.

6. Your Tomato Seedlings are Growing Slowly

If your tomato seedlings are growing too slowly or seem “stunted,” there are a few possible causes; 

  • One reason might be that they’re not getting enough light. Tomato seedlings need at least 12 hours of light per day, so if they’re not getting that much, they may start to stretch out and become leggy.
  • Another possibility is that the soil is too cold. Tomatoes prefer soil that’s around 70 degrees Fahrenheit, so if it’s colder than that, their growth may slow down.
  •  Finally, they may not be getting enough fertiliser. 


Be sure to fertilize your tomato seedlings every 2–3 weeks with a high-quality organic fertilizer to keep them healthy and growing strong.

7. Brown Leaves on Tomato Seedlings

Brown leaves on tomato seedlings are similar to white spots or patches on tomato leaves. 

Brown spots on tomato seedlings are caused by extreme overwatering or underwatering.


To fix the brown leaves, it’s important to figure out what the underlying problem is.

  • If the soil is too dry, the leaves should be watered thoroughly to increase the moisture levels in the soil.
  • If the soil is too wet, reduce watering and let the soil dry out a bit. Make sure to aerate the soil regularly and always make sure the drainage is working properly.
  • If the tomato seedlings are in direct sunlight for too long, move them into a spot where they get more filtered or indirect light.

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8. Fungal Diseases on Tomato Seedlings

Fungal diseases are one of the biggest problems facing tomato seedlings. Moulds and mildews are types of fungi that can infect tomato seedlings and spread quickly in warm, damp places.


  • The best solution to tomato seedling fungal disease is to use fungicide. Fungicide sprays can be applied every 7-14 days during the season to prevent and protect tomato seedlings from fungus.
  • Fungal diseases on tomato seedlings can be prevented by avoiding overhead watering, providing good air circulation, and keeping the soil moist but not waterlogged. 
  • It is also important to remove infected leaves, destroy diseased plants, and avoid overcrowding seedlings to prevent the spread of fungal infections.

9. Overwatering


Overwatering can keep oxygen from getting to the roots and make it hard for the plants to take in nutrients. Sometimes gardeners can get carried away with watering, thinking that more is better, but overwatering can actually harm the plants.

Incorrect watering

If you water the seedlings at night or in the evening, the moisture can stay on the leaves and create a damp environment where fungi can grow.


  • Use a well-draining potting mix that allows water to drain quickly from the soil.
  • Water your seedlings when the top inch of the soil feels dry to the touch, and avoid watering too frequently.

10. Poor Germination 

Tomato seeds should sprout in a week or two if kept at a warm room temperature and sprayed twice daily. One of the most common problems people have when growing tomato seedlings is poor germination. There are a few things that can cause this, including:

  • Seeds that are too old or have been stored improperly.
  •  Seeds that were not treated before planting (such as with a pre-emergent herbicide).
  • Soil that is too dry or too cold.
  •  Planting depth that is too shallow or too deep.


If you are having trouble with poor germination, here are a few things you can try:

  •  Use fresh, high-quality seeds. If possible, buy them from a reputable source and plant them within a year of purchase. Store them in a cool, dark place until you’re ready to use them.
  • Treat your seeds before planting. This will help them to germinate more quickly and evenly. You can do this by soaking them in water for 24 hours or by scarifying them(scratching the seed coat with a sharp knife).


Tomato seedlings can experience a variety of problems that can affect their growth and productivity. By reading this article thoroughly, you can easily deal with the problems mentioned above.

Don’t forget to take care of your plants with enough water, sunlight, and fertilizer as they grow.

With a little care and attention, you can get your tomato seedlings back on track!

Happy planting!

Thank you for reading!

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