Basil is a popular herb grown in home gardens worldwide. It has short, green leaves and can add instant flavour to any dish it is added to. Basil is a very refreshing and useful plant to grow at home. However, it does not come without its issues.
One common problem with your basil plants is white spots on the leaves, which can leave you wondering – why do my basil leaves have white spots?
There could be several reasons behind the appearance of white spots on your basil leaves, and in some cases, it can be fatal for the plant as well. White spots on the leaves need to be treated immediately to prevent damage to the whole batch of plants.
But before jumping off on the solution, you need to know the causes behind white spots. Keep reading to get the answer to your question – why do my basil leaves have white spots?
Top 5 Reasons Why Your Basil Leaves Have White Spots
Why do my basil leaves have white spots? This question invades the mind of many plant owners who decide to grow basil in their gardens.
White spots can appear on basil leaves for several reasons. The most common ones include attacks by insects and pests. Fungus is another common reason, and this can be very harmful to the plant as well.
However, not all is lost when you see spots on basil leaves. If they are diagnosed early, the white spots on basil leaves can be treated effectively.
So, to help you find out the real issue behind the white spots, here are the possible reasons to tackle your query – why do my basil leaves have white spots? Let’s begin!
White Spots Caused by Fungus
Fungal diseases could be one of the reasons your basil leaves are full of white spots. The distinctive feature of fungal diseases is that it leaves a powdery material behind on the plants, and these diseases could take over the plant for several reasons.
For example, if you are splashing the leaves of the basil plant with water, the fungal infection can invade the plant as fungus thrives in moist environments.
It could also be that there is a fungus in the soil, and you caused the soil to come in contact with the leaves of the basil somehow; the infection can then spread to the entire plant.
1. White Fungus
White fungus is the most common type of fungus to attack the plant, especially when the plants are damp and the soil is soggy from excess water. This does not necessarily mean that you overwatered the basil plant. The excess moisture could also be due to rainfall.
If you notice that your basil plant is in a wet environment and the soil is soggy, you must take steps to dry the plant, or it can get attacked by white fungus. Once the white fungus takes over and spreads, there is little you can do. The white fungus can easily kill the plant.
In case of such an attack, cut off the leaves with the infection if the attack hasn’t spread yet. Immediately put the plant under sunlight to let it dry or check the soil to ensure there is plenty of room for airflow.
The soil should be well-drained and rich in organic matter. You can also put the plant under a fan.
The white fungus can be observed by the white powdery material and concentric circles it leaves behind on the leaves. You can try using fungicides to treat this infection.
2. Powdery Mildew
Powdery mildew is a common reason for white spots on your plants. It starts as smaller white spots on the upper surface of the leaves and finally invades the whole leaf and leaves behind a powdery material all over.
The good news is that powdery mildew will not kill your basil plant in most cases. However, you must never eat or use a basil leaf covered in powdery mildew in your food. Powdery mildew develops when the weather is either hot and humid or if it is chilly outside.
There are a few methods you can try to deal with this fungal attack. Use neem oil on the plant or a good insecticidal soap. You can also try baking soda and potassium bicarbonate to handle the mildew.
- PURE & NATURAL: Prescribed for Life potassium bicarbonate powder is a pure, single raw ingredient. No additives. No preservatives. No fillers or binders.
- USP GRADE: Our potassium bicarbonate usp grade powder is great for leavening in baking or to use in winemaking. USP grade is an even higher quality than potassium bicarbonate food grade.
- PERFECT FOR YOUR HEALTHY DIET: Our potassium bicarbonate powder is gluten free, vegan and non GMO. All products are 3rd party lab tested, so you can be sure you're getting a potassium bicarbonate supplement that is genuine and as pure as possible.
- CONVENIENT RESEALABLE POUCH: Prescribed for Life potassium bicarbonate for plants comes in a durable, resealable pouch. It’s easy to store and keeps your potassium bicarbonate fresh for maximum long shelf life.
- PREMIUM BULK NUTRITION: Prescribed for Life offer sizes from 0.5 oz to 25 kg (55 lbs) for your bulk potassium bicarbonate needs. Our potassium bicarbonate powder is packaged in the USA in accordance with GMP guidelines.
White Spots Caused By Insects
Insects are another reason you may see white spots on your leaf. They can appear on the upper surface of the leaf or can take up the bottom of the leaf. Insects feed on the sap or the cell membrane of the plant.
Here are the few common insects that attack a basil plant.
3. Leaf miners
These insects leave behind a distinctive pattern on the leaf. They appear as black flies and feed on the foliage and stem of the plant. Leaf miners are not easy to catch as they can attack the leaves at any time of the day.
Thrips are very tiny insects, but they cause serious damage to your plants. They look like white spots on the top of dark green leaves. Thrips can be found either on the top of the leaf or under it.
It usually doesn’t attack the stem and only the leaves. It also folds the leaves over itself to protect itself from predators.
5. Spider mites
Mites are usually found on the underside of the leaves and, if left untreated, can suck the plant to death. They feed on the sap of the leaves, and their infestation shows itself through white spots on the leaves. Mites leave webs under your basil plant, which is a distinctive feature of identifying these insects.
- 100% Cold Pressed & Unrefined - All natural with absolutely no chemicals or additives included to ensure that the neem oil retains its original composition
- Cosmetic grade - The oil is high in antioxidant compounds that soothe the skin
- Organic gardening uses - used in organic gardening to keep plants looking healthy
- Mix with lotions or shampoos - Antioxidants, vitamins and essential fatty acids provide nourishment for hair, nails and skin
- Satisfaction GUARANTEED - If you aren't fully satisfied with our Neem oil, contact us and we will issue a full refund no questions asked
If the soil of your basil plant is deficient in certain nutrients, your plants will be deficient as well. The most common deficiencies of the basil plant include iron and nitrogen deficiency. In these cases, your plant will show white spots as a symptom of deficiency.
Adding a good fertilizer, especially during the growth phase, can solve this issue.
I hope this guide answers your question – why do my basil leaves have white spots? You should ensure that you provide optimal conditions to your basil plants, like ample sunshine, adequate water, and well-drained soil filled with organic matter.
If you have some unique experiences with your basil plant, don’t forget to share them with your fellow gardeners and us.