How to Prevent White Fungus on Tomato Plants 

This guide will address the query, “how to prevent white fungus on tomato plants?’’ We will also discuss if they are a threat, what causes the white fungus, and how to identify and get rid of them. 

How to prevent white fungus on tomato plants?  

The following are procedures to prevent the growth of white fungus on tomato plants. 

  • Bio -fungicide
  • Sulfur spray or sulfur dust 
  • Analyze the dirt
  • Give the plants some space 
  • Stake the plants 
  • Do not water from the top 
  • Get rid of residues after harvesting 

Gardening is a very joyful activity. Therefore, It is very important to understand the plants you are dealing with before handling them. Now we will discuss further some of the ways mentioned above to prevent the growth of the white fungus on your tomato plants 


They are highly used microorganisms that prevent or limit plant diseases. But you need to note that the fungus can become immune to the fungicide as they grow, this is why you should treat your fungus as soon as possible. 

Sulfur spray or sulfur dust 

Do not use the sulfur spray when there’s direct sunlight, it might damage your plant instead of keeping the fungus away. What you should do is apply it on a calm day or in the early morning or mid-evening hours. 

Analyze the dirt 

You can occasionally analyze the nitrogen in the soil around your tomato plants. If the nitrogen levels are too high, you might have a problem, because these high levels might increase fungus growth. 

Give the plants some space 

Grow your tomato plants in a spacious area, and at least 24 inches apart. This will prevent humid accumulation between the plants which is a factor in increasing the spreading of the fungus. 

Is the white fungus on the tomato plants a threat? 

No, the white fungus on the tomato plants is not a threat. As long as you have treated the plant in the ways mentioned above, the plant will survive and the tomatoes can be washed thoroughly to be consumed. However, if the white fungus infected the tomatoes deeply, it is better to throw them away because they are no longer safe for consumption. 

What causes the white fungus on tomato plants? 

We always get surprised when we see these white fungi on our plants, and we always wonder where they came from. 

Following, you can find some of the causes of these white fungi you see on your tomato plants and how they contribute to their growth. 


Remember fungi are living creatures, so if they found appropriate conditions for growth, they won’t hesitate!

When we speak about the atmosphere, we are speaking about temperature and weather conditions. 


High temperatures, early spring, and summer attract fungi and contribute to their growth. Fungi are mostly found in damp, dark, and humid places. You need to take into consideration the seasonal changes when you want to start gardening. 

Weather conditions 

As mentioned above, when it’s hot and humid, the growth increases. But when it’s windy the fungi create spores and these spores travel through the wind to other plants as you will read in the next point. The plants are most susceptible when they are blooming, so pay particular attention to the flowers if the weather is cool and wet. 


Fungi spores are inactive, they are just there in their bubble waiting for the right conditions to wake up and attack the plant! They could be found in the soil most of the time or carried with the wind from another plant or they might end up on your tomato plant from your irrigation water. 

Fungal infection 

Other plants could infect your tomato plants. You should always take utmost care for all your plants, and never transfer the soil of one plant to another or keep them close to one another. 


How can I identify the fungi infection? 

In the first stages of the infection, the plant might look healthy. So make sure to look for the stem in the lower part, if it is wet and water-soaked then the infection starts. Also, if there’s a discoloration in the stems this might mean there’s an infection. When you see dark brown lesions, at this stage the white cotton growth will form under the appropriate humid conditions. 

How to get rid of the white fungus on tomato plants? 

It is never the end when your plant gets infected by these fungi. Below are some techniques to follow when your tomato plants are infected. 

  • Discard diseased plants and stems to prevent cross-contamination. You can find the correct ways to do so here 
  • Replace the infected soil with a clean one 
  • Use a barrier to cover infected growth to prevent the spread 
  • Use horticultural oils and neem oils 


In this brief guide, we addressed the query, “how to prevent white fungus on tomato plants?’’ We also discussed if they are a threat, what causes the white fungus, and how to identify and get rid of them. So to sum up, give your plants care and love so they can give you much more! 

Hope you found this blog helpful, if you have any questions, please let us know. 


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Hi, I am Charlotte, I love cooking and in my previous life, I was a chef. I bring some of my experience to the recipes on this hub and answer your food questions.