Brown Spots on Houseplant Leaves (Causes & Solutions)

I’ve been into houseplant gardening since my childhood. Houseplant problems are inevitable and fixable. Brown spots on houseplant leaves are due to several reasons. Most of these causes are correctible and preventable.

The common causes of brown spots on houseplant leaves are excess lighting, low humidity, pest infestation, leaf spot diseases, watering problems, and fertilization issues. Investigate the houseplant to identify the exact cause and take the appropriate action.

Continue reading this article to learn how to treat brown spots on leaves. Besides that, the information helps distinguish between various causes of dry brown spots on leaves and their preventive measures.

You May Also Read: Black Spots on Houseplant (Causes & Solutions)

Reasons for Brown Spots on Houseplant Leaves

Excess Lighting

Most houseplants hail from the tropical rainforest. These tropical plants can tolerate low lighting conditions since they grow under the canopies.

Too much light from natural or artificial sources can cause brown spots on plant leaves. Other signs of excess lighting are leaves turning brown, pale, and yellow.

Direct sunlight exposure will result in a combination of brown spots, brown leaf tips, pale and yellow leaves. These severe symptoms make houseplants look uglier.

Move the houseplant away from direct sunlight or artificial light. It will help combat the brown spots on the leaves of indoor plants.

Natural sunlight intensity tends to change with seasons. I recommend putting the indoor plants in a spot that receives bright indirect sunlight.

Remember to trim the affected leaves during spring to rejuvenate the indoor plant. Replicate the native growing conditions at home and avoid brown spots on leaf issues.

Scorch damage leaves cannot be undone, and it would be best to take quick action to grow new and healthy leaves. Remove the old leaves to make your indoor plant look healthy again.

Low Humidity

Tropical houseplants thrive in a warm and humid environment. The houseplant enthusiasts have the responsibility to replicate these growing conditions at home.

Brown leaf tips or leaves dropping and flower buds falling off are symptoms of low humidity. The issue is common during cold winter months.

Cold air tends to hold less moisture, and central heating will dry out the air. Brown leaf tips and brown spots on plant leaves will be the leading signs of low humidity.

Use a digital hygrometer to measure the current indoor humidity level. The readings will give you an idea about the struggling houseplant.

Relocate the houseplant to the bathroom with adequate light to correct the tiny brown spots on plant leaves. Another option is to use an electric humidifier to boost indoor humidity.

Pest Infestations

Tiny brown spots on plant leaves are indicators of pest infestations. Spider mites are the leading insects that attack most houseplants.

Mottled leaves and fine webbing on the leaves’ undersides are signs of spider mites. Controlling spider mites is inexpensive and the easiest compared to aphids or scales.

Use room water temperature to wash the affected leaves every week. Maintain high indoor humidity with adequate ventilation to discourage spider mites from spreading.

Other sap-sucking insects that cause brown spots on leaves are aphids, mealybugs, scales, and thrips. These bugs inject the leaves with venom to cause yellow or brown holes.

Always inspect the houseplant for any sign of pests and isolate the plant if you suspect the signs of infestation. Use insecticidal soap spray to eliminate these tiny bugs on the houseplant leaves.

Leaf Spot Diseases

Small brown spots on leaves are due to leaf spot diseases. These brown dots on plant leaves will grow larger and merge depending on the leaf spot condition.

Rust is a leaf spot disease that results in multiple brown spots on plant leaves. The brown bumps on the underside of leaves thrive in wet environments.

Wipe the brown spots and see the behavior of the color. Cut off the affected leaves and discard them to prevent the fungus from spreading. Use a sulfur-based fungicide to treat fungal rust.

Bacterial leaf spot is another cause of wet-looking brown spots on houseplant leaves. Overwatered plants in a humid environment with poor ventilation can get bacteria leaf spots.

Treating bacterial leaf spots is a daunting and intimidating experience. Treat the mild infection and remove the affected leaves or stems. Isolate the plant to prevent the disease from spreading.

Anthracnose causes dark and sunken lesions on the leaves. The fungal disease can also result in multiple tiny brown spots on the leaves of indoor plants.

The fungal condition is fatal for most indoor plants. I recommend isolating the houseplant and removing the affected leaves or stems. Use a copper-based fungicide to treat the mild infection.

Root and stem rot is due to overwatering problems. It makes the plant turn brown or black and feel mushy. Trim the affected roots and re-pot the houseplant to a container with fresh potting soil.

Ensure the container has drainage holes at the bottom to remove excess water. Be sure to provide ultimate houseplant care to avoid future occurrences.

Fungal leaf spots also result in small brown spots on plant leaves. Remove the affected leaves and apply neem oil to the plant. Discard the plant if the neem oil does not treat the problem.

Watering Problems

The inappropriate watering regime can cause brown leaf tips or brown dying leaves. Inconsistent watering habit is responsible for brown dying leaves and houseplants becoming droopy.

Rehydrate the houseplant by soaking the potting mix. Ensure the potting soil does not get soggy in the long run. Use a pot with drainage holes to eliminate excess water from the potting soil.

Houseplants use more water during spring and summer. I recommend watering these tropical plants every week. Reduce the watering frequency during winter due to the dormancy effect.

Use self-watering planters while on vacation. These planters will ensure the houseplants get adequate water to stay alive and healthy.

Fertilizer Problems

Most tropical houseplants can flourish with fertilizer application. But the fertilizer nutrients promote vegetative and healthy growth.

Too much fertilizer application will burn the roots. Brow leaf tips and brown spots on plant stems are the signs of excess salt accumulation in the potting mix.

Remove the brown crusty buildup on the potting soil and flush thoroughly to eliminate the excess salt. Be sure to use distilled water or rainwater rather than direct water from the tap.

Allow the water to run through the potting soil for several minutes. The excess water will drain out through the drainage holes. Do not water the plant until the 2-3 inches of topsoil is dry.

Related Questions

Should I Cut off Leaves with Brown Spots?

Yes. It will help combat the brown spots from spreading to other parts. Besides that, it will make the houseplant look healthy and beautiful.

Yellow Spots on Leaves Indoor Plants

Yellow spots on houseplant leaves are due to inappropriate watering, incorrect lighting, pests, and diseases. Always examine your houseplant to identify the exact cause before fixing it.

Black Spots on Leaves Indoor Plants

Fungal diseases and pest infestations are the leading cause of black spots on houseplant leaves. Other possible causes are bacterial or viral infection, aging, and nutritional deficiency.

Final Word

It can be intimidating to figure out the exact cause of brown spots on houseplant leaves. I recommend taking the time to inspect and examine your affected houseplant.

The information above will help you identify the possible causes and their respective solution. It would be best to review your care requirements and provide better conditions.

Feel free to share your experience dealing with the tiny brown spots on indoor plants. Besides that, share this informative article with other houseplant enthusiasts in your communities.