White spots on tomato leaves are an eyesore for your average vegetable garden carer and a cause for great concern. Your plant can develop white spots or patches due to several reasons.

Side view of hybrid tomato leaves

Continue reading our guide below to find out what they are, how to identify them, and how to get rid of them for a healthy plant and plentiful yield.

What Causes White Spots On Tomato Leaves?

Powdery mildew, sunburn and lack of nutrients are just some causes that might be responsible for producing white spots on the leaves of tomato plants. Continue reading to find out what the other reasons are and how to deal with them.

– Powdery Mildew

Powdery mildew is the most common reason why tomato plants suffer from spots in their leaves. If your tomato plants are affected by it, the leaves will have whitish or grey powdery spots all over their surface .

A powdery mildew infection doesn’t really damage the plant that much, but it will lead to a lower yield, change the taste of your tomatoes for the worse, and lead to stunted growth of the entire plant.

– Sun Scalding 

Sun scalding has also been known to cause white leaves on tomato plants. This occurs mostly when the tomato plant is exposed to very intense sunlight for prolonged periods of time. White sunburn spots on the leaves also develop when a plant is grown indoors at first and then suddenly moved outdoors and placed under direct sun.

Prevention is the best cure when it comes to white spots on the leaves caused by sun scalding. Don’t place your plant under the very hot sun, and when shifting plants from indoors to outdoors, keep them under a shade first and gradually acclimatize them to the sun.

If your plant seems to suffer from a problem such as this, immediately remove it from under the sun and get rid of the dried leaves.

– White Leaves Due To Lack Of Nutrients

White spots on tomato plant leaves can also be a sign of a lack of nutrients. Nitrogen or phosphorus deficiencies will cause the leaves to turn white or yellowish in color.

Magnesium and calcium deficiencies will turn the leaves white with the veins still retaining their green color. You can remedy this problem by using a good-quality fertilizer that is rich in these particular nutrients.

– Late Blight

Late blight is a rapidly spreading fatal fungal infection that commonly attacks the tomato plant during the rainy fall season. It is a serious condition that can wipe out an entire plant within weeks.

Late blight will cause powdery white spots to develop on the leaves along with rotten brown spots on the stem of the plant. Plants that are kept in humid, dark, and moist conditions are the most at risk.

Causes of White Spots on Tomato Leaves

– Pest Damage By Stinkbugs

Attack by certain pests can also cause tiny white spots on tomato leaves that are so irritating to get rid of. You can find out what bugs are responsible for this along with our expert tips to deal with them below.

  • If you notice white specks on tomato leaves of your plant along with puncture wounds on ripe tomatoes, this is almost always a sign of a stink bug infestation.
  • These pesky insects love ripe tomatoes and are a common hazard.
  • White spots caused by stink bug attacks will appear fibrous and tough.
  • The use of a mild, non-toxic insecticide will get rid of the bugs. Remove the affected leaves and your plant will thrive again.
  • Applying neem oil on the leaves will also get rid of these insects from your plant.

What Causes a Powdery Mildew Infection?

Powdery mildew is a fungal infection that can be caused by several fungi that attack plants that are kept in moist and humid conditions. Tomato plants become suspect to mildew infections when they are overwatered, not receiving enough light, or under high humidity conditions.

Many tomato carers tend to over-fertilize their plant, which can also lead to white spots on tomato plants by powdery mildew. 

How To Deal With White Spots Caused By Powdery Mildew

You should deal with powdery mildew infections as soon as you start noticing its white patches on tomato leaves. Here are some of the ways you can treat a powdery mildew infection.

– Prune The Infected Leaves

  • The first thing you should do is to get rid of all the leaves that have white spots on them. This will prevent the infection from spreading to other parts of the plant. Use sharp gardening shears or scissors to remove these leaves.
  • If a large number of leaves are infected, only remove the most severely affected ones. Pruning a large majority of leaves will lead to the death of your tomato plant.
  • Always disinfect and clean the shears and scissors that you use for pruning infected leaves. You don’t want to spread these fungal spores to other plants.

– Go Organic With Neem Oil

  • Neem oil is a natural antifungal and antiseptic remedy for treating white spots by mildew infection.
  • Apply it to the white spots on the leaves to get rid of powdery mildew the organic way.
  • Neem oil will also protect your tomato plant from common plant bugs like mealybugs, aphids and beetles.

– Milk Spray Will Also Rid Of Mildew White Spots

  • Milk is another great natural remedy to treat white leaves on tomato plants. 
  • Mix milk with water in a ratio of 2:3 and spray this mixture on your plant.
  • This spray should be applied only once per week. In a couple of weeks, your plant will get healthier.

How To Deal With Spots Caused By Late Blight?

Take rapid action as soon as you notice your tomato plant developing this condition. Prune the affected leaves off and remove all the dead and decayed tissue. Use a copper fertilizer once every week until you see some improvement in the condition of your tomato plant. 

Never use the pruned leaves of a plant suffering from late blight as compost. In fact, our gardeners strongly advise against planting any part of the affected plant in the tomato bed during the next planting season. 

 

Preventing Tomato Leaves From Getting White Spots

Taking care of your tomato plant preemptively so that it doesn’t get white spots is something you should always work on. Here are our top tips for you to chew on.

– Keep Plants At A Distance From Each Other

  • All tomato plants should have a distance of at least 18 to 24 inches between them.
  • Plants that are huddled and kept very close together tend to experience high levels of humidity around them.
  • Air circulation is also compromised, leading to fungal infections like powdery mildew and late blight.

– Provide Enough Sunlight

  • Sunshine is very important for tomato plants. Not only does it help them grow and develop food and strength but it also protects the plant from unwanted attacks by fungi.
  • Make sure your plant is placed under sunlight of adequate intensity for a good amount of time.
  • Tomato plants need six to eight hours of natural light on a daily basis.

– Ventilation Is A Must For Your Tomato Plant

  • Plants should always be placed in a well-ventilated area with plenty of space for adequate air circulation to occur.
  • Fungal infections responsible for tomato plant leaves turning white love to grow in cramped, poorly ventilated plants.

Remove the white spots of tomato leaf

– Groom Regularly 

  • Maintain regular grooming of the plant. Remove old and yellowing leaves every other month.
  • Old leaves tend to unnecessarily take up the essential nutrients and energy that your tomato plant needs for its growth and survival.

– Lower Humidity Around Your Plant

  • Humidity levels around tomato plants should not exceed 70 percent.  
  • Use a dehumidifier if you live in a humid region.     

Growing Tomato Plants: Tomato Leaf Problems

Growing healthy tomato plants is the dream of every vegetable gardener. However, many things can go wrong with this plant if it is not taken care of properly. Take a look at this list to find out the tomato leaf problems most often faced by gardeners.

  • Development of white spots on the leaves.
  • Formation of white, fibrous patches on the leaves.
  • Wilting of leaves.
  • Yellowing of leaves.
  • Leaves turning brown and falling down.

a man with tomato leaves

Conclusion

White patches on tomato leaves are a common inconvenience faced by tomato gardeners all over the world. Now that you are well-versed in its causes and management, let us recapitulate the most important points.

  • Powdery mildew, a fungal infection, is the primary culprit when it comes to white flecks on tomato leaves. 
  • Your tomato plant might suffer from Powdery mildew if it is kept under hot, humid conditions with poor air circulation.
  • Mildew can be treated by pruning all the infected leaves displaying white spots. 
  • Neem oil and milk mixed with water are very effective natural remedies for treating this condition.
  • Exposing your plant to very intense sunlight will also whiten its leaves. 
  • White spots can also indicate a lack of nutrients such as calcium, nitrogen, and phosphorus. Treat your plant to a fertilizer rich in these nutrients.
  • Stink Bugs are pests that attack ripe tomatoes and produce white, fibrous patches on its leaves. Get rid of them by using a good insecticide.
  • Late blight is another fungal infection that attacks tomato plants during the hot, rainy season before fall. It can destroy a plant within weeks and needs aggressive management by debridement and strong antifungals.
  • Protect your tomato plant from white spots on the leaves by keeping them in a brightly lit area with proper circulation, humidity levels and sunshine.
  • Humidity levels around tomato plants should not exceed 70 percent.

We’re confident that with the tips and tricks presented in this article, you are never going to have a bad day with your tomato plants ever again!

5/5 - (17 votes)
Evergreen Seeds