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Troubleshooting Brown, Rust-like Specks on Monstera Leaves

Discover effective treatments and preventive measures from my personal experience to keep your Monstera thriving.

As a proud Monstera parent, I understand the joy these lush, green plants bring into our homes. 

However, it’s not uncommon for Monstera owners to encounter various issues with their plants. 

One particularly troubling problem is the appearance of brown, rust-like specks on the leaves. 

In this guide, I’ll share my personal experience and the steps I took to address and prevent this issue, ensuring your Monstera remains healthy and vibrant.

Table of Contents

Identifying the Problem

When I first noticed the brown, rust-like specks on my Monstera leaves, I was quite alarmed. 

These spots can vary in size and may be spread across multiple leaves, potentially impacting the overall health and appearance of the plant

Here’s a detailed breakdown to help you identify this issue:

Description and Symptoms

The affected leaves typically exhibit small, brown or rust-colored specks. These spots may be scattered across the leaf surface or concentrated in specific areas. Over time, they can grow in size and number, leading to the deterioration of the leaf tissue. 

Some common symptoms include:

  • Discoloration: Initially, you might notice tiny yellowish spots that eventually turn brown or rust-colored.
  • Leaf Damage: As the spots spread, they can cause the leaf tissue to become brittle and break away.
  • Spread to Other Leaves: If left untreated, the infection can spread to other leaves, affecting the plant’s overall health.

Possible Causes Based on Visual Identification

Determining the exact cause of these spots is crucial for effective treatment. 

From my experience and research, the primary culprits are usually:

  • Rust Fungus (Puccinia sp.): A fungal infection that causes rust-colored spots on the leaves.
  • Brown Spots Infection: Another type of fungal or bacterial infection that results in brown spots on the leaves.

Proper identification of the cause is essential as it dictates the treatment approach. 

In the next sections, I’ll delve into how to distinguish between these issues and the specific steps to treat them.


Regularly wipe down Monstera leaves with a damp cloth to remove dust and prevent pest infestations.

Possible Causes and Diagnoses

Rust Fungus (Puccinia sp.)

Rust fungus is a common fungal infection that affects many types of plants, including Monstera

This fungus appears as small, rust-colored spots on the leaves. 

Over time, these spots can merge, causing significant damage to the leaf. Here are some key points to help you identify rust fungus:

  • Color and Texture: The spots are typically a rusty-brown color and may feel powdery to the touch.
  • Location: These spots often appear on the underside of the leaves but can also spread to the top surface.
  • Spread: The infection can spread quickly in humid conditions, making it essential to address it promptly.

Brown Spots Infection

The appearance of brown spots on Monstera leaves can be caused by a fungal or bacterial infection. 

This type of infection is characterized by the following symptoms:

  • Spot Characteristics: The spots are generally brown and may have a yellow halo around them. They can start small and expand over time.
  • Tissue Damage: Infected areas may become dry and brittle, leading to leaf damage and potential leaf drop.
  • Environmental Factors: Overwatering, poor air circulation, and high humidity levels can exacerbate this infection.


Correctly identifying the cause of the brown spots is crucial for effective treatment. 

In the next sections, I will share the steps I took to treat and prevent these infections in my Monstera plants.


Rotate your Monstera plant every few weeks to ensure even growth and prevent it from leaning towards the light source.

Treatment Options

For Rust Fungus (Puccinia sp.)

Dealing with rust fungus requires immediate action to prevent the infection from spreading and causing further damage to your Monstera. 

Here are the steps I followed:

  • Remove Affected Tissues: Carefully cut off the infected leaves or parts of the leaves using sterilized scissors. It’s crucial to dispose of these leaves properly and avoid composting them, as the fungus can survive in compost and reinfect your plants.
  • Apply Copper Fungicide Spray: Use a copper fungicide spray, which is effective in controlling rust fungus. Ensure you cover all surfaces of the leaves, both top and bottom. Follow the instructions on the fungicide packaging for the correct dosage and frequency.
  • Improve Air Circulation: Rust fungus thrives in humid conditions. To prevent recurrence, increase air circulation around your Monstera by placing it in a well-ventilated area. You can also use a fan to improve airflow.
  • Maintain Proper Light Levels: Ensure your Monstera receives adequate light. Indirect bright light is ideal for Monstera plants. Proper lighting helps reduce humidity levels and strengthens the plant’s overall health.
  • Avoid Misting: While misting can be beneficial for humidity-loving plants, it can also promote fungal growth on Monstera leaves. If you need to increase humidity, consider using a humidifier instead of misting directly on the leaves.

For Brown Spots Infection

Treating brown spots caused by fungal or bacterial infections involves a slightly different approach. 

Here’s how I managed this issue:

  • Assess the Severity: If less than 50% of the leaf is infected, you may not need to remove the entire leaf. However, if more than 50% is affected, it’s best to cut off the leaf to prevent the infection from spreading.
  • Cut Off Infected Leaves: Use sterilized scissors to remove the infected leaves. Make sure to sterilize your scissors before and after use to avoid spreading the infection. You can use rubbing alcohol or a bleach solution for sterilization.
  • Treat the Plant: After removing the infected leaves, treat the plant with a fungicide or bactericide recommended for houseplants. Follow the product instructions carefully for effective treatment.
  • Sanitize Your Tools: Always sanitize your pruning tools after each use. This step is crucial to prevent the spread of pathogens to other parts of the plant or to other plants in your collection.
  • Repeat Treatment: Continue to monitor your Monstera and repeat the treatment every two weeks as needed. Consistent treatment is key to fully eradicating the infection.
  • Adjust Watering Practices: Overwatering can contribute to fungal and bacterial infections. Ensure your Monstera’s soil is well-draining and water the plant only when the top inch of soil is dry. Proper watering practices help prevent root rot and other moisture-related issues.

By following these steps, I was able to successfully treat and manage the brown spots on my Monstera. 

Next, I’ll share some preventive measures to keep these issues from returning.

Quick Tip:

Use rainwater or distilled water for your Monstera to avoid the build-up of minerals found in tap water, which can harm the plant over time.

Preventive Measures

Preventing future infections is crucial to maintaining the health and beauty of your Monstera

Here are some preventive measures that I have found effective:

  • Ensure Adequate Light: Place your Monstera in a location where it receives bright, indirect light. Adequate lighting helps the plant to grow strong and reduces the risk of infections.
  • Improve Air Circulation: Make sure there is good airflow around your plant. This can be achieved by using a fan or by placing the plant in a well-ventilated area. Good air circulation helps to reduce humidity levels, which can deter fungal growth.
  • Proper Watering Practices: Avoid overwatering your Monstera. Let the top inch of soil dry out before watering again. Using a well-draining soil mix and a pot with drainage holes can help prevent root rot and other moisture-related problems.
  • Avoid Leaf Misting: While misting can increase humidity, it can also create conditions favorable for fungal infections. Instead of misting, use a humidifier if your home is very dry.
  • Regular Inspection: Frequently inspect your Monstera for early signs of disease. Catching infections early makes them easier to treat and prevents them from spreading to other plants.
  • Cleanliness: Keep the area around your Monstera clean. Remove fallen leaves and debris that can harbor pests and pathogens. Clean your plant’s leaves occasionally to remove dust and potential pathogens.
  • Quarantine New Plants: When introducing new plants to your collection, keep them in a separate area for a few weeks to monitor for any signs of pests or diseases before placing them near your Monstera.

Implementing these preventive measures has helped me maintain a healthy Monstera collection, free from persistent infections. 

Did You Know?:

The Monstera plant is also known as the "Swiss Cheese Plant" because of the unique holes and splits in its leaves.


Dealing with brown, rust-like specks on your Monstera leaves can be challenging, but with the right approach, you can restore your plant to its vibrant health. Here’s a quick recap of the key points:

  • Identify the Problem: Accurately diagnosing whether your Monstera is suffering from rust fungus or a brown spots infection is crucial for effective treatment.
  • Treatment: Follow specific steps to treat rust fungus and brown spots infection, including removal of affected tissues, application of appropriate fungicides, and maintaining proper air circulation and light levels.
  • Preventive Measures: Implement preventive measures such as ensuring adequate light, improving air circulation, practicing proper watering, and regularly inspecting your plants.

By following these guidelines, I’ve been able to keep my Monstera plants healthy and thriving. 

The key to successful plant care is regular monitoring and early intervention. 

Don’t wait until a small issue becomes a major problem. 

With consistent care and attention, your Monstera can grow beautifully, adding lush greenery to your home.

Feel free to share your own experiences and tips in the comments below. 

Let’s foster a community of Monstera enthusiasts who support each other in achieving plant care success.

Embrace the spirit of horticulture and spread the seeds of wisdom

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