Croton Leaves Turning Black? (10 Causes & How To Fix Them)

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Croton plants are gorgeous tropical plants known for their vibrant, multi-colored leaves.

They make excellent houseplants and can even be used as outdoor plants in warm climates.

However, croton leaves turning black is a common problem that gardeners face.

There are several reasons why croton leaves might turn black.

Here you’ll learn 10 possible causes of black leaves on croton plants and how to fix the problem.

Why Are My Croton Leaves Turning Black, and How Can You Fix It?

There are several reasons croton leaves might turn black.

The most common reasons are:

1. Overwatering

One of the most common reasons for croton leaves turning black is overwatering.

Croton plants are native to tropical climates and prefer consistent moisture.

However, they cannot tolerate soggy soil.

If you overwater your croton plant, the leaves will start to turn black and drop off.

How To Tell If You Are Overwatering Your Croton Plant

There are a few telltale signs that you are overwatering your croton plant.

  • The leaves will turn yellow, brown, and eventually black.
  • The leaves will also start to drop off the plant.
  • The stems will become soft and limp.
  • The root system will start to rot.

If you see any of these signs, it is essential to take action to correct the problem. Otherwise, your croton plant will eventually die.

How To Fix Overwatering

If you think you are overwatering your croton plant, the first thing you need to do is stop watering it so much.

Allow the soil to dry out completely before watering again.

Croton plants need to be watered about once a week or when the soil is dry to the touch.

Be sure to check the soil before watering to avoid overwatering.

Repot your croton plant in a well-drained potting soil mix is also a good idea.

This will help to improve drainage and prevent overwatering in the future

You also need to ensure you use a pot with drainage holes.

2. Pest Infestation

Another common reason for croton leaves turning black is a pest infestation.

Croton plants are susceptible to various pests, including aphids, whiteflies, and mealybugs.

These pests feed on the plant’s sap, which can cause the leaves to turn black.

Pest infestations can also lead to other problems, such as leaf drop and stunted growth.

How To Tell If Your Croton Plant Has A Pest Infestation

A few signs will help you tell if your croton plant has a pest infestation.

  • The leaves will have black or brown spots.
  • The leaves will begin to yellow and then turn brown or black.
  • The leaves will start to drop off the plant.
  • The leaves have a sticky coating.
  • You will see the pests themselves on the leaves or stems.

How To Control Pests On Croton Plants

You can do a few things to get rid of pests on croton plants.

  • Try to remove the pests by hand. This can be time-consuming, but it is the most effective way to get rid of pests.
  • Use a product like neem oil, which will kill the pests and prevent them from coming back.
  • Use a product like insecticidal soap, which will kill the pests but is safe for humans and animals.

Always follow the directions on the product label when using any pesticide.

3. Fungal Disease

Fungal diseases are another common reason for croton leaves to turn black.

Fungal diseases are caused by fungi in the soil and the plant’s surface.

The most common fungal diseases that affect croton plants are black spot and anthracnose.

These diseases cause black or brown spots on the leaves and leaf drop.

Fungal diseases are more common in humid conditions.

How To Tell If Your Croton Plant Has A Fungal Disease

A few signs will help you tell if your croton plant has a fungal disease.

  • The leaves will have black or brown spots.
  • The leaves will begin to yellow and then turn brown or black.
  • The leaves will start to drop off the plant.
  • You will see a powdery substance on the leaves or stems.

How To Control Fungal Diseases On Croton Plants

You can do a few things to control fungal diseases on croton plants.

  • Water the plant at the base, not from above. This will help to prevent the fungus from spreading.
  • Remove any affected leaves and dispose of them.
  • Apply a fungicide to the plant. Always follow the directions on the product label.
  • Use a natural fungicide, such as cinnamon or baking soda.

4. Bacterial Disease

Bacterial diseases are another common reason for croton leaves to turn black.

The most common bacterial disease that affects croton plants is bacterial leaf spot.

This disease causes black or brown spots on the leaves and leaf drop.

Bacterial diseases are more common in humid conditions.

How To Tell If Your Croton Plant Has A Bacterial Disease

A few signs will help you tell if your croton plant has a bacterial disease.

  • The leaves will have black or brown spots.
  • The leaves will begin to yellow and then turn brown or black.
  • The leaves will start to drop off the plant.
  • You will see a slimy substance on the leaves or stems.
  • The affected area will be wet or moist.

How To Control Bacterial Diseases On Croton Plants

You can do a few things to control bacterial diseases on croton plants.

  • Water the plant at the base, not from above. This will help to prevent the bacteria from spreading.
  • Remove any affected leaves and dispose of them.
  • Apply a bactericide to the plant. Always follow the directions on the product label.
  • Use a natural bactericide, such as vinegar or hydrogen peroxide.

5. Fertilizer Burn

Fertilizer burn is another common problem that can cause croton leaves to turn black.

Fertilizer burn happens when the plant is given too much fertilizer.

The fertilizer will burn the roots of the plant, which will damage the leaves and cause them to turn black.

How To Tell If Your Croton Plant Has Fertilizer Burn

A few signs will help you tell if your croton plant has fertilizer burn.

  • The leaves will have black or brown spots.
  • The leaves will begin to yellow and then turn brown or black.
  • The leaves will start to drop off the plant.
  • The leaves will have a burnt appearance.

How To Control Fertilizer Burn On Croton Plants

You can do a few things to control fertilizer burn on croton plants.

  • Flush the soil with water to remove the excess fertilizer.
  • Do not fertilize the plant for a few weeks.
  • Prune the affected leaves.

6. Sunburn

Sunburn is another common problem that can cause croton leaves to turn black.

Croton plants need bright indirect light to thrive.

However, sunburn happens when the plant is exposed to too much direct sunlight.

The sun will damage the leaves and cause them to turn black.

How To Tell If Your Croton Plant Has Sunburn

A few signs will help you tell if your croton plant has sunburn.

  • The leaves will have black or brown spots.
  • The leaves will begin to yellow and then turn brown or black.
  • The leaves will start to drop off the plant.
  • The leaves will have a burnt appearance.

How To Fix Sunburn On Croton Plants

You can do a few things to fix sunburn on croton plants.

  • Move the plant to a shady area.
  • Prune the affected leaves.
  • Provide the plant with extra water, but do not water the leaves.

7. Heat Stress

Heat stress is another common problem that can cause croton leaves to turn black.

Heat stress happens when the plant is exposed to too much heat.

The heat will damage the leaves and cause them to turn black.

How To Tell If Your Croton Plant Is Heat Stressed

A few signs will help you tell if your croton plant is heat stressed.

  • The leaves will have black or brown spots.
  • The leaves will begin to yellow and then turn brown or black.
  • The leaves will start to drop off the plant.
  • You will see wilting or drooping leaves.

How To Fix Heat Stress In Croton Plants

If you think your croton plant is heat-stressed, you can do a few things to try and fix the problem.

  • Move the plant to a cooler location.
  • Make sure the plant has enough water.
  • Remove any dead or dying leaves.
  • Add some mulch around the plant to help keep the roots cool.
  • Give the plant some shade if it is in full sun.

8. Root Rot

Root rot is another common problem that can cause croton leaves to turn black.

Root rot happens when the plant roots are damaged or start to die.

This can be caused by too much water, not enough drainage, or a variety of other problems. When the roots are damaged, it can cause the leaves to turn black.

How To Tell If Your Croton Plant Has Root Rot

A few signs will help you tell if your croton plant has root rot.

  • The leaves will have black or brown spots.
  • The leaves will begin to yellow and then turn brown or black.
  • The leaves will start to drop off the plant.
  • You will see wilting or drooping leaves.
  • The roots will be mushy or black.

How To Fix Root Rot In Croton Plants

If you think your croton plant has root rot, you can do a few things to try and fix the problem.

  • Remove the plant from the pot and check the roots.
  • Trim away any damaged or black roots.
  • Replant the croton in a fresh, sterile potting mix.
  • Water the plant carefully, making sure not to overwater.
  • Let the soil dry out between waterings.

9. Frost Damage

Frost damage is another common problem that can cause croton leaves to turn black.

Frost damage happens when the plant is exposed to freezing temperatures.

The frost will damage the leaves and cause them to turn black.

How To Tell If Your Croton Plant Has Frost Damage

A few signs will help you tell if your croton plant has frost damage.

  • The leaves will be black or brown and wilted.
  • The leaves will feel papery and dry.
  • The stems will be brittle.
  • The leaves will turn yellow or red before they turn black.

How To Fix Frost Damage

If you think your croton plant has frost damage, you can do a few things to try to fix the problem.

  • Move the plant to a warmer location.
  • Protect the plant from future frost damage by covering it with a cloth or blanket.
  • Provide the plant with extra humidity by misting it with water or placing it on a pebble tray.
  • Give the plant extra water to help it recover from the damage.

10. Physical Damage

Physical damage is another common problem that can cause croton leaves to turn black.

Physical damage happens when the plant is damaged by something physical, like being hit by a rock or being chewed on by an animal.

The damage will cause the leaves to turn black.

How To Tell If Your Croton Plant Has Physical Damage

A few signs will help you tell if your croton plant has physical damage.

  • The leaves will have black or brown spots.
  • The leaves will be ripped or torn.
  • The stems will be broken.

How To Fix Physical Damage In Croton Plants

If you think your croton plant has physical damage, you can do a few things to try and fix the problem.

  • Remove any dead or dying leaves.
  • Trim away any damaged stems.
  • Repot the plant in fresh soil.
  • Give the plant some extra TLC and make sure it gets enough water and light.

Final Thoughts

Croton leaves turning black is a relatively common issue that several factors can cause.

In most cases, it is a sign of stress or disease and can be remedied with the proper care.

Be sure to pay close attention to your croton plant and take action as soon as you notice any leaves turning black.

With the proper treatment, your croton plant will be healthy and vibrant in no time!