White Spots on Basil Leaves: What Are They?

Last Updated on April 15, 2024 by Real Men Sow

White spots on basil leaves can be alarming for herb gardeners. This severe condition should be checked on the plant and its surroundings. Growing basil problems can manifest as white spots on basil leaves.

What are the white spots on basil leaves?

There are many reasons why basil white spots may occur. These possible causes of white spots in basil plants before you get too concerned:

Natural Variegation

Sometimes white marks or patterns on basil leaves are due to one of several basil diseases. Other times it could be due to the variety of basil. Variegated basil plants are sometimes available. 

Variegation can become worse if your basil plant has exposure to more sunlight. You will need to determine if your basil plants have variegation tendencies. You can then investigate other possible causes of white spots if you believe this is not true.

Insects and Infestations

Many insects are easily visible; some may require careful observation. These insects are pests of the basil plant and can also cause problems.


Aphids are one the most common pests of plants. Tiny insects suck the sap from your Tulasi basil leaves using their sharp mouths. The young aphids are white and appear in clusters. Adult aphids are seen in many colours, such as black, yellow, green, and brown. You should now be able to identify them and determine if they are white spots on your basil leaves.


Mealybugs are small, soft-coloured bodies that look like tiny tufts or cotton. They also cluster on the undersides and stems of basil plants, sucking the sap and causing them to curl up and fall.


Mites leave white webs under basil leaves. These tiny insects live under the leaves and suck the sap from the leaves. A mild infestation of mites shows up as small white spots on basil leaves. 


Thrips are tiny insects that live on basil leaves but rarely on stems. They have semi-translucent, white bodies and curved bodies. To protect themselves from predators, they hide in the basil leaves.


Whiteflies will gather around your Sweet Thai growing leaves and fly away only when disturbed. They aren’t true flies, despite their name. Whiteflies are soft-bodied insects that are closely related to mealybugs and aphids. These insects are active in the morning and often live in large groups. Whiteflies can sap the leaves and cause them to turn yellow.

Solutions to Insect Infestations


Ladybugs are natural predators of aphids, mealybugs, mites, and whiteflies. Encouragement of a large ladybug population can have remarkable benefits. Ladybugs are naturally drawn to large numbers of their prey. You may purchase them from both online and physical commercial shops.

Neem Oil

The fantastic properties of Neem oil can help control pests that attack your basil plants. You can spray your plants with neem oil by mixing it with water and some dishwashing detergent. However, neem oil may cause your basil leaves to taste bitter. Because of the bitter taste of neem oils, pests will either die or leave because they don’t like the unappetizing flavour. Spraying neem oil early in the morning is preferable to spraying it late in the evening.

These basil leaves may still be edible. However, it is not recommended to eat them right away. Let the basil leaves sit for a while to allow the neem oil to evaporate. Wash the basil leaves once more before using them.

Insecticidal Soaps

The effectiveness of insecticide soaps is remarkable in eliminating pests from your plants. Insecticidal soaps are made with potassium salts of fatty acids. They do not harm plants but can be fatal to soft-bodied pests like mealybugs and aphids. It is best to apply insecticidal soaps in the morning or later in the afternoon.

Although insecticide soaps are safe for humans and large mammals, washing the treated leaves before applying them to your skin is best.

Fungal Infections

White Fungus

White fungus is often responsible for white spots on basil leaves. These are most common when the weather conditions are often wet for extended periods.

If you notice white spots on your basil leaves due to the white fungal, get rid of them immediately. The infected leaves need to be in isolation, where they can’t infect other plants. Allow your infected plants to get more sunlight and airflow.

Baking soda and potassium bicarbonate are also effective anti-fungal sprays. You can also purchase commercially available fungicides. As a precaution, be sure to follow the instructions on the package.

Powdery Mildew

Due to the high moisture content of hot and cold air, powdery mildew can cause white spots on basil leaves. Powdery mildew can be treated with neem oil sprays. Prevent them from using insecticide soaps.

Other Basil Diseases and Issues That Are Equally Concerning

These conditions can cause white spots on basil leaves, but they are not always fatal. These are some basil-related diseases that you should be aware of:


Introduce natural predators to your garden to discourage the presence of slugs. Slugs are a favourite food of chickens, ducks and toads and these animals will quickly kill them. One popular way to make beer-soaked deep dishes is to use half of a deep dish. The beer’s yeast attracts the slugs, making them sink into the deep dish and drown.

Stop slugs from climbing up your property by placing crushed eggshells around the plants or wrapping copper wire around them.

Fusarium Wilt

Fungal seeds or dirt contaminated with fungal spores are its cause. These results in underdeveloped growth, yellowing of the leaves, brown spots or streaks on the stalks and twisted stalks.

Fusarium wilt is incurable but can be treated by destroying the infected plants. Gardeners recommend soaking the whole plant in a fungicide and letting the spray drip into the soil. Use this approach with extreme caution to ensure safety.

Root Rot

Root rot can be caused by overwatering for too long. This can sometimes be caused by fungal spores in soil that is activated by overwatering. Root rot can cause the plant’s death. Basil can be prevented from root rot by being planted in well-drained soil. Let the soil dry slightly before watering.

Bacterial Leaf Spot

The Pseudomonas-Cichorium bacteria can cause brown and black spots on the basil plant’s leaves and stalks. Although there is no cure for the condition, you can minimize it by ensuring enough airflow between plants. Instead of watering the plant’s leaves, it is better to water the soil.

Nitrogen Deficiency

Basil plants that are deficient in nitrogen can become small and unwell. This can be corrected by ensuring that your basil plants receive enough nitrogen through either organic or inorganic fertilizers and soil supplements.

It is possible to have your soil tested for deficiencies and then amend it by using the right formulations to correct them.

How To Prevent White Spots on Basil Leaves?

After identifying the causes of white spots in basil leaves, we’ll also discuss the different methods to keep them healthy. These are the best ways to ensure a healthy and happy basil plant.

  • Sunlight Your basil plants need to get the right amount of sunlight. Basil plants need 6-8 hours of sunshine daily to stay healthy.
  • Air Basil plants need good airflow to avoid any pests or infections.
  • WaterYour basil plant’s health can be positively affected by the amount and timing of your watering. Your water should be sufficient to stimulate growth and prevent fungal infestations.
  • Use pesticides only when necessary Pests can sometimes sneak into gardens, no matter what we do. You should use insecticides with care, commercial or homemade organic.
Real Men Sow
Real Men Sow

Hello, I’m Pete and I’m currently based in the west of Scotland, in a small place called Rosneath, where I’m exploring my garden adventures. I personally started gardening around 6 years ago and initially, I started out by growing my favorite fruits and berries, such as strawberries, Raspberries & Gooseberries. Since then I’ve added a lot of vegetables and working closely with my neighbor, it’s been a lot of fun.