Why Is My Basil Turning Yellow? (Exploring Causes and Solutions)

If you’re an avid gardener, you may have encountered the unfortunate sight of yellowing basil leaves.

While this can be disheartening, it’s important to understand why this may be happening and what you can do to fix it.

In this article, we’ll explore the potential causes of your basil turning yellow and offer some solutions to get your plant back on track.

From too much water to nutrient deficiencies, we’ll look at the most common culprits.

We’ll also provide tips on how to detect the cause of the problem so you can take the appropriate steps to get your basil back to health.

Short Answer

Basil can turn yellow for a few reasons.

It could be due to too much direct sunlight, too little water, or a nutrient deficiency.

Make sure your basil is in a spot with plenty of indirect sunlight, and water it regularly.

You can also try adding a balanced fertilizer to the soil to ensure your plant is getting all the nutrients it needs.

Causes of Yellowing Leaves

When it comes to why your basil is turning yellow, there are several potential causes.

The most common causes include too much or too little water, insufficient light, nutrient deficiencies, or pests.

Too Much Water: If your basil is getting too much water, it can cause the leaves to yellow and even rot. This is because the soil is staying too wet for too long, which can cause root rot and fungal diseases. To prevent this, make sure you are watering your basil only when the soil is dry, and make sure the pot has adequate drainage.

Too Little Water: On the other hand, if your basil isnt getting enough water, it can also cause the leaves to yellow. Make sure you are providing your basil with adequate water, but dont overwater it. A good rule of thumb is to water your basil when the top inch of soil is dry.

Insufficient Light: Basil needs at least 6 hours of direct sunlight per day in order to stay healthy and vibrant. If your basil isnt getting enough light, it can cause the leaves to yellow. If you think this might be the cause of the yellowing leaves, try moving the plant to a brighter spot.

Nutrient Deficiencies: Basil needs certain nutrients in order to stay healthy. If its not getting enough of these nutrients, it can cause the leaves to yellow. To remedy this, try fertilizing your basil with a balanced fertilizer every few weeks.

Pests: Finally, pests can also cause basil to yellow. Look for small holes in the leaves, as well as signs of insects like aphids or whiteflies. If you do find signs of pests, try using an insecticidal spray or neem oil to get rid of them.

Too Much Water

When it comes to why your basil is turning yellow, too much water could be to blame.

Overwatering can cause the basil to become waterlogged, leading to yellowing of the leaves.

The roots of the plant become deprived of oxygen, which leads to a decrease in photosynthesis and causes the leaves to turn yellow and eventually die off.

It is important to monitor the soil moisture of your basil plant and ensure that it is not receiving too much water.

The best way to do this is to stick your finger into the soil and assess the moisture content.

If the soil is overly saturated, then you should reduce the frequency of watering.

If the soil is dry, then you should increase the frequency of watering.

Too Little Water

Having healthy, green basil leaves is a sign of a thriving plant, so if you notice your basil turning yellow it could be due to insufficient watering.

Basil requires regular watering in order to thrive and not become dehydrated.

Its important to check the soil moisture and water your basil regularly to make sure its getting enough water.

If the soil is dry to the touch, its time to give your plant a drink.

Too little water can cause the leaves to yellow as the plant is unable to absorb enough nutrients from the soil.

The leaves may also become limp and wilted as a result of dehydration.

To fix this issue, make sure to water your basil regularly and keep the soil moist but not soggy.

You can also mulch around the plant to help retain moisture, or consider installing a drip irrigation system to ensure your basil is getting the right amount of water.

Insufficient Light

One of the most common causes of basil turning yellow is insufficient light.

Basil is a sun-loving plant and needs at least six hours of direct sunlight a day to remain healthy.

If the plant is not getting enough sunlight, the leaves will start to turn yellow.

To prevent this from happening, make sure to place the basil in an area that receives plenty of direct sunlight.

If you are growing your basil indoors, you may need to use a grow light to give it enough light.

Additionally, make sure to rotate the plant regularly so that all of its leaves get equal amounts of light.

Nutrient Deficiencies

Nutrient deficiencies can be a common cause of yellowing basil leaves.

The most common nutrient deficiencies for basil are nitrogen, phosphorus, and potassium.

If the soil is lacking in these essential nutrients, the plant will struggle to survive and the leaves will start to yellow.

To prevent this, make sure to fertilize your basil regularly.

You can use either a balanced fertilizer or a fertilizer specifically formulated for basil.

Additionally, adding compost or organic matter to your soil can also help provide the necessary nutrients for your basil plant.

If you suspect a nutrient deficiency, you can also use soil testing kits to measure the nutrient levels in your soil.

That way, you can know for sure and take steps to add the necessary fertilizers.


Pests can be one of the culprits behind your basil leaves turning yellow.

Aphids, spider mites, thrips, and whiteflies are some of the most common pests that can cause basil to yellow.

These pests feed on the plants sap, leaving behind yellow patches or spots on the leaves.

If you notice yellowing leaves along with webbing, this is a sign of spider mites.

If you see small, white, flying insects hovering around the plant, these are whiteflies.

If you notice a sticky coating on the leaves, this is a sign of aphids.

To get rid of these pests, you can use a neem oil or insecticidal soap solution.

You may also want to introduce beneficial insects such as ladybugs, lacewings, or predatory mites to your garden to help keep the pest population in check.

Additionally, you can use a soft brush or a cotton swab to remove any visible pests from the plant.

Finally, make sure to keep your garden clean by removing any debris and weeds that could be harboring pests.

Detecting the Cause

When it comes to pinpointing the cause of your basil turning yellow, its important to be a detective and assess the environment in which the basil is growing.

There are a few potential culprits that could be responsible for the yellowing leaves, such as over- or under-watering, insufficient light, nutrient deficiencies, or pests.

To determine the cause, it is important to check the soil and water levels, and look for any signs of pests or disease.

If your basil is in a pot, begin by checking the soil moisture.

Basil likes well-draining soil, so if the soil is too wet, this could be causing the yellow leaves.

If the soil is too dry, this could be the cause as well.

If you are unsure of the moisture levels, sticking your finger into the soil a few inches and feeling the moisture can help you determine if it is too wet or dry.

If the soil is too wet, let the pot dry out a bit and if it is too dry, give it some water.

Next, it is important to check the light levels.

Basil loves plenty of sunshine, so if the pot is not receiving enough light, this could be contributing to the yellowing.

Move the pot to a sunnier spot and see if the leaves start to turn green again.

The next step is to check for nutrient deficiencies.

Basil needs a little bit of fertilizer to thrive.

If the potting soil you are using does not contain fertilizer, you may need to add a bit to the soil.

You can also look for signs of pests or disease.

If you see any bugs or signs of disease, you may need to treat the plant with an insecticide or fungicide.

By taking these steps and doing a bit of detective work, you should be able to identify the cause of the yellowing leaves and correct it.

With a bit of care and attention, you should be able to restore your basil to its vibrant green.

Final Thoughts

Basil plants turning yellow can be caused by many factors, including too much or too little water, insufficient light, nutrient deficiencies, or pests.

By assessing the environment in which the basil is growing, and checking the soil and water levels, the cause of the yellowing leaves can usually be determined.

With a bit of detective work, the cause can be corrected and the basil restored to its vibrant green.

Now that you know the potential causes of yellowing basil, you can take the necessary steps to help ensure your basil stays healthy and happy!

Peter Kirsch

Peter is an avid gardener and herbalist. He loves learning about the healing and medicinal properties of herbs and enjoys writing about them. He’s been passionate about herbs since he was a child and has learned a lot about them over the years. He’s written several articles for various publications, all about herbs and their uses. He’s also spoken at several conferences and workshops about the topic.

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