Basil Leaves Turning White | Top 3 Reasons and Fixes

Basil leaves turning white is among the most common symptoms of infection to look out for if you grow basil. Different basil varieties, including lemon, Holy, Genovese, and Thai can experience this problem. Nevertheless, white on basil indicates that the chlorophyll in the plant’s leaves is degenerated and requires an immediate fix. 

Basil plant leaves turning white can point to a series of underlying problems that may also need different solutions. However, first look closely at your plants to make a proper diagnosis for the reason behind the basil leaves turning white. Remember, the first step to fixing a problem is identifying it correctly. Start by looking at the growing conditions of your basil plants. 

White stuff on basil stem may arise from bad cultural practices rather than a disease or insect infestations. However, poor cultural practices can also attract insects and diseases that my be reason behind basil leaves turning white. Make sure the plants are grown in well-draining soil rich in organic nutrients and have access to adequate water and sunlight. 

The Top Reasons Behind Basil Leaves Turning White 

Basil is one of the most coveted vegetables, mainly grown for its leaves used in cooking. As such, basil leaves turning white signifies problems, and you should take it very seriously. So, what does it mean when basil leaves turn white? Gardenterprise offers insights to help you to understand why are the leaves on my basil plant turning white and how to address the problems effectively. 

Many questions come to mind whenever you see your basil turning white. The first question is usually why basil leaves turn white. There are two main reasons for basil leaves turning white: fungal infections or insect infestation. Basil leaves attract many insects, including spider mites, mealybugs, leafhoppers, thrips, aphids, and whiteflies. 

Insects usually cause irregular and random damage to the plant leaves, but the spots do not become significant with time. However, fungal infections start as small patches that spread onto the leaf surface, creating more significant marks that eventually cover the entire leaf. If your basil leaves are tuning white with similar signs, the reasons are definitely due to fungal or insect infestation. However, nutrient deficiencies can also be a reason behind basil leaves turning white. 

1.     Common Basil Diseases 

Disease infestation is one of the main reasons why basil leaves turn white. Diseases usually start as uniform spots on the leaf surfaces, creating powdery mildew. In contrast, what does it mean when basil leaves turn yellow? Or, why basil leaves turning black should concern you. 

Yellow indicates downy mildew, while black or brown represents bacterial leaf spots or fusarium. The areas will increase in size and eventually cover the entire leaves if you don’t address the issue on time. Here are the common basil diseases and their symptoms to help you to understand what it means when basil leaves turn white.  

Powdery Mildew Basil 

Powdery mildew is the most prevalent disease that causes white basil leaves. It often occurs during cool nights and warm days. The infection begins as small white spots on the upper leaf surface and spreads to cover the entire leaf with a powder-like coating. The disease grows fast on tender fresh leaves, so you should regulate fertilization to prevent the spread.

Although powdery mildew does not impact permanent plant damage, that could occur in severe cases. Perhaps, you are also wondering whether white spots on basil leaves are safe to eat. Please don’t eat basil with white areas caused by powdery mildew. 

Downy Mildew 

Downy mildew is another common disease that usually manifests through basil leaves turning yellow white. It starts as small yellow patches on the leaf surface. Downy mildew spreads through wind, developing a fuzzy gray growth on the bottom of the leaves that will then drop off. The development may look like a layer of dirt, but a closer look can help you to spot it on time.

Warm temperatures and high humidity levels can accelerate downy mildew development, with Holy basil leaves turning brown. 

Usually, contaminated seeds and infected leaves introduce it to the plants. However, wind can also disperse it to healthy plants. Downy mildew progresses rapidly and can finish off your plants quickly if you don’t treat them immediately and effectively. 

Fusarium wilt 

Fusarium wilt is among the most devastating fungal infections on basil. A soil-borne pathogen called Fusarium oxysporum causes it, and contaminated seeds and soils can introduce and spread it. One of the reasons for its devastation is that the disease can survive over a more extended period as pores, causing new infections. It mainly manifests through fresh basil leaves turning brown, with twisted stems and stunted growth.

Bacterial Leaf Spot 

You may wonder, what does it mean when basil leaves turn brown? In that case, focus more on bacterial leaf spots. The disease’s symptoms include brown and black water-soaked spots on the leaves and parts of the stems. Fresh basil leaves turning black can also signify bacterial leaf spots. The marks are irregular and can spread to the entire leaf surface over time. 

Gray Mold 

Gray mold is the answer to why are my basil leaves turning gray. Its symptoms include brownish to grayish fungal growth on the leaves and stem. While it may be confused with downy mildew, gray mold is usually denser and fuzzier. You will notice the basil leaves turning gray, wilting, and eventually falling off the plant. The entire plant may die if the disease becomes severe and develops on the main stem. 

2.     Basil Insects and Pests 

Insect and pest infestations also have a more significant role to play in the discoloration of plant leaves. They cause damage by feeding on the plant leaves, creating small white spots on the upper leaf surfaces. Some insects and pests can multiply very quickly and overwhelm the plant, and could be the reason behind the basil leaves turning white. That implies you should conduct frequent inspections on your basil plants to identify and stop them on time. Nonetheless, the following are the common pests and insects behind basil leaves turning white. 

Aphids 

Aphids usually thrive in colonies, feeding on plant leaves and stems. While white aphids are the most common varieties, other colors also exist. The insects suck juices from the basil leaves, creating small and irregular spots on the leaf surfaces. And this can also be the reason behind the basil leaves turning white.

Spider Mites 

Spider mites are tiny pests that feed on basil leaves and stems. Although detecting them can be extremely difficult, you can quickly tell spider mites’ infestation through small dots on the leaf surfaces. Thus, spider mites can be the reason behind the basil leaves turning white.

Leafhoppers 

Like other basil pests and insects, leaf hoppers also such juices from the leaves, creating small white dots across the surface. Their wedge-shaped bodies and quick movements make them quite hard to spot. However, the damage caused by those insects looks like trails or channels on the surface. Hence, a possible reason behind the basil leaves turning white. 

Thrips 

Thrips are tinier and slender pets that often hide inside new buds or on the leaf undersides. Infestations can sometimes cause the leaves to close up. Thrips leave irregular silvery or white spots across the leaf surface. Infested leaves also turn brown as they degenerate and die. 

Mealybugs 

Mealy bugs are also tiny and white. The pests often live in leaf axils and crotches from where they suck off plant juices. Unlike the other basil pests, mealybugs are tropical insects that do not thrive in cold temperatures. However, they can devastate plants grown indoors or in warm outdoor environments. Hence, a possible reason behind the basil leaves turning white.  

Whiteflies 

Whiteflies have light-colored bodies that appear as white spots. Although they feed on plant leaves, white flies are less invasive than most pests. You can quickly drive them away from your basil plant by shaking it. 

3.     Nutrient Deficiencies 

The lack of or inadequate nutrients can also cause discoloration of basil leaves. However, different colors represent unique nutrient deficiencies. So, what causes basil leaves to turn brown? Or, what does it mean when basil leaves turn yellow? Brown or purple spots on basil leaves are symptoms of phosphorus deficiency. 

Basil leaves turning yellow indicate a lack of iron or nitrogen. Basil leaves turning pale green could also mean a deficiency in some nutrients. Nonetheless, the resulting spots and discoloration on the leaves become dead over time as the conditions persist, eventually turning brittle and fading to white. 

Unlike diseases, pests, and insects, detecting nutrient deficiencies in plants requires more detailed diagnostic approaches. Instead of rushing to add nutrients to the plants, you should first conduct a proper soil test. That will enable you to determine and supplement the deficient nutrients with the utmost accuracy and precision. Once you notice the nutrient deficiency behind the basil leaves turning white, add the appropriate fertilizer.

Strategies for Fixing Basil Leaves Turning White 

The above sections have comprehensively explained why my basil leaves are turning white. It has also explained why basil leaves turning brown should concern you. The main reasons include diseases, pests, insects, and nutrient deficiency. Now that you know what causes basil leaves to turn white, you should also understand how to solve the problems. 

Various strategies exist for addressing Holy basil leaves turning black, white, yellow, or brown. Here’s how to treat white spots on basil leaves. 

Treatments for Diseases Behind Basil Leaves Turning White

The best way to control fungal diseases, such as mildew on basil, is by embracing improved growing practices. Fungicides are better preventive measures against fungal infections, but you should apply them before the growth begins. Various fungicides exist in the market but be careful to read and follow the instructions on the label. Use the right product to address the problem of basil leaves turning white.  

Potassium Bicarbonate 

Potassium Bicarbonate is one of the best commercial products for addressing mildew and other fungal diseases in plants, which can be the reason behind the basil leaves turning white. It is mainly available as a liquid, sprayed over the plant to prevent and treat infections. Making your potassium bicarbonate solution at home is not recommended since it could kill the plants and pollute the environment. 

Baking Soda  Remedy for Basil Leaves Turning White

Baking soda is an effective anti-fungal spray that can help eradicate pests and insects from your basil plants. You can easily make it at home by mixing one tablespoon of baking soda, one tablespoon of mild dish soap, and one tablespoon of vegetable oil in a gallon of water. Spray baking soda weekly for better results. 

Unlike fungal diseases, bacterial infections on basil, such as bacterial leaf spots, have no cures. The only way to stop this bacterial infection is to remove and destroy all the infected basil plants. 

Remedies for Basil Pests and Insects  

You can use various insecticides and pesticides to remedy your basil leaves turning white. They can kill many pests and insects, allowing your plant to grow strong and healthy. 

Leafhoppers and whiteflies are flying insects that may not be eradicated by spraying. However, applying a systemic insecticide to the soil can kill the insects as they feed since the plant will absorb the chemicals. A strong water spray from your garden hose can also send the pests flying away. Insecticides can be harmful, so make sure you use one labeled safe for food crops. 

Neem oil 

Neem oil is a plant-based product with a strong odor that induces a smothering effect on insects. Mix two tablespoons of neem oil in a gallon of water to create the ideal solution for spraying your basil leaves. Insecticidal soap, dish soap, and diatomaceous earth can eradicate basil pests and insects.  

Basil leaves turning white is a common problem experienced in both indoor and outdoor basil plants. The above article has discussed the top reasons for basil leaves turning white and how you can effectively eradicate the problem. 

FAQs

Why are my basil leaves losing color?

Many reasons can cause the discoloration of basil leaves. However, the leading causes of basil leaf discoloration include diseases, pests, insects, and nutrient deficiencies. Any of those elements can make basil leaves lose color, turning them to white, yellow, gray, black, or brown, depending on the specific cause and severity of the infection. 

Why are my herb leaves turning white?

Herb leaves turn white due to pest infestation, diseases, and nutrient deficiency. However, poor cultural practices can also make leaves turn white. 

What does an overwatered basil look like?

Overwatered basil looks more like plants that do not receive adequate water. Pale and wilted leaves are the main symptoms, but you may also notice mushy and rotten roots. 

Why is my basil plant turning silver?

Basil plants turning silver is a symptom of downy mildew. The disease is common among indoor plants since it thrives in environments with high moisture levels. 

What does diseased basil look like?

Various symptoms can help you to tell if diseases infect your basil. Leaf coloration is one of the main signs of diseased basil, but wilting and stunted growth suggest infections. 

What does an unhealthy basil plant look like?

Diseases, pests, nutrient deficiency, and poor cultural practices can make your plants unhealthy. They can manifest various symptoms, including leaf discoloration, twisted stems, rotting stems and roots, and stunted growth. 

What happens when basil leaves turn white?

Basil leaves turning white suggest diseases, insects, or nutrient deficiency. Nonetheless, the leaves may maintain white or change into other colors, then wilt and wither before falling off. 

How do you fix white plant leaves?

Various remedies can fix white plant leaves, including fungicides, pesticides, insecticides, and better cultural practices. However, the treatment to use will mainly depend on the problem’s causes and the infestation’s severity. 

Henry Mugambi

Henry Mugambi

Take a look at this guy. He's almost in his 40s, but he looks like he could be in his 20s. That's because he's a gardener—and a damn good one, too. He's been gardening since he was a little kid, and he loves nothing more than sharing his tips with others.He started blogging a few years ago, and his blog has since become a go-to source for gardening information. His audience trusts him because he knows his stuff, and he always offers sound advice that helps people get the most out of their gardens.

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