Why Are the Basil Leaves Turning Brown? [Causes & Treatment]

Basil plants are easy to grow aromatic herbs. And they need low maintenance and care. Yes! You read that right.

Still, the basil faces some problems. Browning leaves of basil is one of the biggest problems for the growers.

But the question; why do basil plant leaves turn brown?

In short, Lack of sunlight, over and under watering, size of pots, environmental stress, diseases, and pets are the main culprits of Basil leaves turning brown.

For your convenience, Here I will discuss the causes of basil leaves to turn brown with the best solutions.

 So, if you want to keep your basil from turning brown, read the article carefully-

 Causes and Treatment of Basil Leaves Turning Brown

1.Lack of Enough Sunlight

You can grow basil indoors and outdoors. But only one thing you should consider the perfect condition of growing places. Basil loves the sun. It can grow well in full and partial sunlight. Basically, the basil plants need 6 to 8 hours of sun in a day.

If the basil doesn’t get sufficient sunlight, the leaves turn brown, or turn brown on edges, and curl. Also, the plants grow with long stems with a few leaves due to the lack of sunlight. 

Control Measures

If you grow basil plants in containers, place them where they get enough sunlight. South-facing windows can be the place where basil loves to grow.

For inground basil plants, plant them in a sunny place and make sure they must get afternoon sun. Never park your car in front of basil for a longer period of time. Remember; direct sunlight doesn’t do any harm to basil.


Overwatering can be the culprit behind the brown leaves of basil. Some growers think the more water, the more leaves. But it is wrong. Too much water can cause root rot. As a result, wilting takes place, and the leaves turn yellow. Lastly, the leaves become brown and fall off.

Control Measures

Apply water to your basil when they need water actually. Now the question; how much and how often water does basil need?

Generally, 1 inch of water per week is enough for basil. But you should remember, basil likes moist soil but doesn’t like stagnant water. So, the schedule doesn’t always work. You must water the plant when the soil dries.

If you face the browning leaves problem for potted basil, make sure the container has a drainage hole and the soil has good drainage facilities.

Repotting is the best way to revive the affected potted basil. But if the root damage entirely, sorry to say, you are lost your basil. You should plant new baby basil.

Note: You can also keep basil from wilting by following those steps. And if you protect your plant from wilting, then automatically you can protect your basil leaves from turning brown. Also, never spray water on the basil leaves, it causes the brown spots on basil.


Underwatering also shows the same symptoms. If you don’t apply water when the soil dries, the basil leaves start to curl and brown.

Control Measures

I have told that the basil needs 1-inch water per week. But you should apply more water depending on the weather condition. If the weather is too hot and windy, the soil dries more quickly. So, you must apply water more frequently.

The moisture meter(Our pick: Atree Soil Soil Tester Kits) can help in this case. Also, you can poke a stick or finger to feel the dryness of the soil. If the soil feels hard, add moisture to the soil. But be careful about water lodging conditions that cause root rot.

4.Root Bound

Root bound occurs for potted basil plants mostly. You know, healthy roots mean healthy plants. And the roots need space to grow and thrive successfully.

But if you grow basil in a small container, the roots can’t grow more root tips and become bounded. As a result, the plants can’t absorb sufficient water and nutrients and the leaves become yellow and brown.

Control Measures

Remove the affected basil plant gently from the existing pot. Loosen the root-soil carefully and repot the plant in a large pot or container. Generally, 8 inches in diameter and 10 inches deep container/pot is perfect for growing basil.

5.Soil and Fertilizer

Faulty soil and improper fertilization cause the fresh basil leaves to turn brown. Highly acidic and highly alkaline soil causes browning and curling of basil leaves. Plus, Too much chemical fertilizer increases the chance of attack the diseases and pests.

Control Measures

Basil loves neutral or slightly acidic soil. Also, they don’t like too much organic content in the soil. You can plant your basil in sandy soil. Sandy soil protects the basil’s root from root rot.

And apply organic herb fertilizer twice in the growing season. Here is the recommended fertilizer for your basilJobe’s Organics Herb Plant Food.

6.Plant Stress

Any non-ideal growing conditions such as too much replanting, Temperature change, improper watering, too much fertilizer, and some diseases cause plant stress. And the stress basil shows brown leaves, curl leaves as the sign of stress.

Control Measures

Grow the basil in a healthy and perfect condition. Never apply fertilizer to newly planted basil. Never change the pot or pot position continuously and try to protect the basil from frost. You can install a grow light in cold conditions.

7.Diseases of Basil

Some fungal diseases such as fusarium wilt and damping-off cause of browning leaves of basilSometimes wilting and yellow to brown spots appear on stems of the basil.

Control Measures

Spray fungicide to control fungal diseases. Damping-off can be treated by fungicide but it is difficult to save plants from fusarium wilt by spraying fungicide if it develops successfully.

So, prevention is the best way to protect your basil from fungal diseases. Here is the organic copper fungicide that you can spray- Bonide 811 Copper Fungicide

8.Pests on Basil Plants

Some pests suck the cell sap and damage the plant tissue. Spider mites, scales, aphids,water-sucking bugs, and thrips are the destructive insects for basil. They can damage the basil causing the basil leaves to turn brown with some black to brown spots.

If you notice any pest activity on basil or hang the insects under the leaves, then insects may be the culprit.

Control Measures

Organic or inorganic insecticide, neem oil(azadirachtin), insecticidal soap for the plant, or pyrethrin can help you to keep away the insects from your basil. Here are the recommended insecticides that you can pick for your basil-

  1. Safer Brand Ready-to-Use End All Insect Killer
  2. Natria 706240A Organic Plant Protection From Pests and Diseases Neem Oil

You can also make insecticide for your basil at home. Here are the steps –

  1. Take a gallon of freshwater.
  2. Mix 2-3 tablespoons of dish soap.
  3. Add 1 tablespoon of neem oil or vegetable oil.
  4. Shake the solution and spray it on the plants.

Warning: Basil plant sensitive to insecticide and fungicide. So, before spraying thoroughly, test on some leaves and wait 24 hours. If you don’t notice any burn sign, apply thoroughly. But if you notice any burn sign, dilute the solution.

Frequently Asked Questions

#How do you tell if basil is overwatered or Underwatered?

The basil shows the same symptoms because of overwatering and underwatering. So, you should observe a few more things to understand.

Touch the soil, poke your finger, or poke a dry stick into the soil. If you feel moisture, and the plants show yellow, brown leaves, and wilting conditions, then the symptoms appear due to the overwatering.

But if you notice dry soil and yellow to brown colored leaves with wilting, then underwatering may be the culprit.

Using a moisture meter (Our pick: Atree Soil Soil Tester Kits) is the best to tell if basil is overwatered or Underwatered.

#Are basil leaves turning brown still okay to use?

You can use yellow basil leaves. But you should notice that the leaves don’t have any bad smell.

But my recommendation; dry the browning basil leaves and use as spices.


Basil leaves have a lot of health benefits. So, you plant to grow basil. But when the plants start thriving you notice your basil leaves are turning brown.

Sounds sad, right? Basil growers can feel your pain. Because most of the growers are facing the problem or faced the problem.

So, I wrote this article to tell you the reason for basil leaves turning brown and how you deal with it. Hope you found the best solution here.

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