Why Are My Basil Leaves Turning Yellow? (13 Solutions)

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Basil is a versatile herb that’s commonly used in cooking.

It has a strong, pungent flavor and is often used to add a burst of flavor to dishes.

Basil leaves are also used as a decoration or garnish.

While Basil is generally easy to grow, sometimes the leaves can turn yellow.

This can be due to several factors, including disease, pests, or simply poor growing conditions.

If your Basil leaves turn yellow, here are 10 possible causes and solutions.

What Causes Basil Leaves to Turn Yellow and How To Fix It

Basil (Ocimum basilicum) is a popular herb used in many cuisines around the world.

It’s also easy to grow indoors on a windowsill or outdoors in a garden.

Basil leaves are usually green, but if they turn yellow, it can be due to several reasons.

Here are some common causes of yellowing basil leaves and what you can do about it:

1. Too Much Water

Overwatering Basil plants is a common problem, as the leaves will begin to turn yellow and fall off.

This problem is typically caused by too much water in the soil, which can drown the roots and prevent the plant from getting the oxygen it needs.

If your Basil plant is wilting and the leaves turn yellow, check the soil to see if it’s too wet.

The soil should be moist but not soggy.

How To Fix It

If your Basil plant is wilting and the leaves turn yellow, it’s likely because the plant is getting too much water.

You’ll need to let the soil dry out completely before watering again to fix this problem.

You can also try using a well-draining potting mix to help prevent overwatering in the future.

Basil plants need to be watered regularly, but you should allow the soil to dry out between waterings.

If the soil is too wet, try increasing the time between waterings or choose a pot with drainage holes to help improve drainage.

2. Not Enough Water

Basil leaves can turn yellow for several reasons, but one of the most common causes is lack of water.

When Basil plants don’t get enough water, their leaves will start to turn yellow and eventually brown and wilt.

Basil is a very sensitive plant, and even just a little bit of drought can cause its leaves to turn yellow.

Basil needs to be watered regularly, especially during hot weather.

How To Fix It

The good news is that you can easily prevent this by making sure to water your Basil plant regularly and deeply.

If you notice that the leaves are starting to turn yellow, increase the frequency and amount of water you’re giving the plant.

Basil likes to be kept moist, so make sure the soil is never allowed to dry out completely.

They need to be watered at least once a week and more often during hot weather.

3. Lack of Light

Basil is a sun-loving plant, and it needs at least 6 hours of sunlight per day to thrive.

If Basil plants don’t get enough light, their leaves will start to turn yellow.

This is because the plant cannot produce enough chlorophyll, which is responsible for giving Basil its green color.

How To Fix It

To fix this problem, move your Basil plant to a brighter location.

If you’re growing Basil indoors, place it near a south-facing window where it will get the most sunlight.

Basil plants need at least 6 hours of sunlight per day, so make sure the plant is getting enough light.

However, too much direct sunlight can also cause Basil leaves to turn yellow.

4. Too Much Light

While Basil needs a lot of light to grow, too much sunlight can be harmful to the plant.

If Basil plants are exposed to too much direct sunlight, their leaves will start to turn yellow.

This is because the plant is producing too much chlorophyll in an attempt to protect itself from the sun.

How To Fix It

If your Basil plant is getting too much sunlight, move it to a shadier location.

If you’re growing Basil indoors, place it near a north-facing window where it will get indirect sunlight.

Basil plants need at least 6 hours of sunlight per day, so make sure the plant isn’t getting too much or too little light.

5. Nutrient Deficiencies

Basil plants can also suffer from nutrient deficiencies, which can cause their leaves to turn yellow.

Basil’s most common nutrient deficiency is nitrogen, but the plant can also lack other essential nutrients like phosphorus and potassium.

A nutrient deficiency can be caused by several factors, including poor soil quality, incorrect fertilizer ratios, and inadequate watering.

How To Fix It

If you suspect that your Basil plant is suffering from a nutrient deficiency, the best course of action is to get a soil test done.

This will help you determine which nutrients are lacking and how to best amend the soil.

You can also try using a fertilizer high in nitrogen, phosphorus, and potassium to help correct the nutrient deficiency.

Basil plants need to be fertilized every 2-4 weeks during the growing season.

6. Overfertilization

While Basil plants need to be fertilized regularly, it’s important not to overdo it.

Overfertilizing Basil plants can cause their leaves to turn yellow or brown.

This is because the plant is getting too much nitrogen, which causes the leaves to turn yellow.

It can also cause the plant’s roots to burn, leading to Basil leaves turning brown and wilting.

How To Fix It

If you think your Basil plant has been overfertilized, flush the soil with water to remove any excess fertilizer.

You can also try moving the plant to a new pot with fresh, unfertilized soil.

Basil plants should be fertilized every 2-4 weeks during the growing season.

7. Pest Infestation

Basil plants can also be affected by pests, which can cause their leaves to turn yellow or brown.

The most common pests that affect Basil plants are aphids, whiteflies, and spider mites.

These pests suck the sap from Basil plants, which can weaken the plant and cause its leaves to turn yellow.

Pest infestations can also lead to Basil leaves turning brown and wilting.

How To Fix It

If you think your Basil plant has a pest infestation, the best course of action is to treat the plant with neem oil or an Insecticidal soap.

You can also try to remove the pests by hand. Use a cotton swab or a Q-tip dipped in rubbing alcohol to kill the pests.

You can also try using a strong blast of water from a hose to remove the pests from your Basil plant.

8. Cold Weather

Basil plants are native to tropical climates and can’t tolerate cold weather.

If Basil plants are exposed to temperatures below 50°F, their leaves will turn yellow.

This is because the plant is going into shock and trying to protect itself from the cold.

Frost can kill Basil plants, so it’s essential to bring them indoors or cover them up if you live in a cold climate.

How To Fix It

Bring it indoors and place it in a warm, sunny location if your Basil plant is exposed to cold weather.

Cover it with a frost blanket or burlap sack to protect it from the cold if you can’t bring the plant inside.

Basil plants should be kept above 50°F at all times.

9. Basil Downy Mildew

Basil downy mildew is a fungal disease that affects Basil plants.

This disease is caused by the fungus Pseudoperonospora cubensis and can cause Basil leaves to turn yellow or brown.

Basil downy mildew thrives in humid conditions and can quickly spread to other Basil plants.

Signs of Basil downy mildew include yellow or brown spots on the leaves, wilting, and leaf drop.

How To Fix It

If your Basil plant has Basil downy mildew, the best action is to remove all affected leaves.

Destroy any infected leaves that you find to prevent the fungus from spreading.

You can also try treating the infected plant with a fungicide.

Basil downy mildew is difficult to control, so it’s essential to take preventive measures to avoid it.

10. Potting Soil Issues

Basil plants need well-draining, nutrient-rich soil to thrive.

If Basil plants are grown in potting soil that’s too dense or doesn’t have enough nutrients, their leaves can start to turn yellow.

The best way to avoid this problem is to use a high-quality potting mix for Basil plants.

You can also add some organic matter to the soil to improve its drainage and nutrient content.

How To Fix It

If your Basil plant is grown in potting soil that’s too dense or doesn’t have enough nutrients, repot the plant in a high-quality potting mix.

You can also add some organic matter, such as compost, to the soil to improve its drainage and nutrient content.

Basil plants need well-draining, nutrient-rich soil to thrive, so provide them with the best growing conditions possible.

11. Overcrowding

Basil plants need room to grow and should be planted in individual pots.

If Basil plants are overcrowded, their leaves can start to turn yellow.

This is because the plants compete for space, light, and nutrients.

Basil plants that are overcrowded will also produce fewer leaves and flowers.

How To Fix It

If your Basil plants are overcrowded, repot them in individual pots.

Be sure to provide each plant with enough space to grow.

Basil plants need room to breathe and should be planted in individual pots.

12. Transplant Shock

Basil plants can go into shock when they are transplanted.

This is a normal reaction and nothing to worry about.

Basil plants need time to adjust to their new environment and usually recover within a few days.

Symptoms of transplant shock include yellow leaves, wilting, and leaf drop.

How To Fix It

If your Basil plant is experiencing transplant shock, give it time to adjust to its new environment.

Basil plants need time to acclimate to their new surroundings and usually recover within a few days.

Be sure to water the plant regularly and keep it in a warm, sunny location.

13. Natural Leaf Yellowing

It’s normal for Basil leaves to turn yellow as they age.

Basil plants produce new leaves all the time, and the older leaves will eventually turn yellow and die off.

This is a natural process and nothing to worry about.

Basil plants will continue to produce new leaves as long as they are healthy and happy.

How To Fix It

There’s no need to fix Basil leaves turning yellow due to age.

Just remove the affected leaves and dispose of them.

Basil plants will continue to produce new leaves, so don’t worry about the plant losing its foliage.

Why Are My Basil Leaves Turning Yellow With Brown Spots?

Basil leaves can turn yellow with brown spots due to several different reasons.

Basil downy mildew, nutrient deficiencies, and herbicide damage are common causes of Basil plant turning yellow with brown spots.

When diagnosing the problem, it’s important to look for other symptoms that can help you narrow down the cause.

  • Basil leaves turning yellow with brown spots due to herbicide damage will also have a burnt or scorched appearance.
  • Basil leaves turning yellow with brown spots due to nutrient deficiencies will often have pale green or yellowish-green leaves.
  • Basil downy mildew will cause the leaves to turn yellow and brown, and they will also have a powdery or fuzzy appearance.

Why Are My Basil Leaves Turning Yellow and Curling?

Basil leaves can turn yellow and curl due to several different reasons.

Basil downy mildew, nutrient deficiencies, heat stress, and pest infestations are common causes of Basil leaves turning yellow and curling.

When diagnosing the problem, it’s important to look for other symptoms that can help you narrow down the cause.

  • Basil leaves turning yellow and curling due to downy mildew will also have a powdery or fuzzy appearance.
  • Basil leaves turning yellow and curling due to nutrient deficiencies will often have pale green or yellowish-green leaves.
  • Basil plants experiencing heat stress will often have wilted or drooping leaves.
  • Basil leaves infested with pests will have small holes or chewed edges.

Why Are My Basil Leaves Turning Yellow With Black Spots?

Basil leaves can turn yellow with black spots due to several different reasons.

Basil is a very sensitive plant, and even small changes in its environment can cause Basil leaves to turn yellow with black spots.

The most common reason Basil leaves turn yellow with black spots is lack of water.

Basil leaves will turn yellow if the plant is not getting enough water.

Basil leaves will also turn yellow if the plant is getting too much water.

Overwatering Basil plants can cause the roots to rot, which will cause the leaves to turn yellow and eventually die.

Should I Remove Yellow Leaves From Basil Plant?

If you have a basil plant, you may notice that the leaves turn yellow.

While this is a common problem, it can be frustrating to see your plant suffer.

So, should you remove yellow leaves from Basil plants?

The answer is yes and no. If the leaves are only slightly yellow, they can still be used for cooking.

However, if the leaves are very yellow or starting to brown, it is best to remove them.

This will help the plant focus its energy on producing healthy new leaves.

If you decide to remove yellow Basil leaves, be sure to do so gently.

These leaves are delicate and can easily be damaged.

Use sharp scissors or pruning shears to make clean cuts.

Basil plants are generally very resilient, so don’t be afraid to trim them back.

Final Thoughts

Basil leaves can turn yellow for a variety of reasons.

Most often, it’s due to a lack of nutrients or too much water.

Basil plants also need well-draining, nutrient-rich soil to thrive.

If your Basil plant’s leaves turn yellow, try one of the solutions listed above.

With a bit of care and attention, you can get your Basil plant back to its green and healthy self in no time.

Thanks for reading!