Monstera Leaves Turning Black [Causes and How to Fix]

Monstera, famous for its deeply lobed, gigantic green leaves, can become a victim of the unfair practice, turning the edges of leaves yellow and black.

So read along to gain detailed information about the causes and solutions to resolve the problem.

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Monstera Leaves Turning Black (Causes and How to Fix)

Despite being a resilient and robust plant, Monstera is not free of problems.

After a certain stage, the quality and amount of factors like light, soil, water, and humidity might fluctuate, causing black spots on the leaves of Monstera.

Fortunately, the condition is reversible if noticed before the situation worsens.

1. Improper Watering

Both overwatering and underwatering are responsible for the Monestra leaves turning black.

It might be baffling to figure out what exactly is going on with your Monstera as the plant exhibits similar symptoms in both issues.

However, differences exist, which you can spot easily.

You can correct the situation by placing the pot under direct light for a day and bring indoors.

Also, if the roots feel mushy, cut off all the damaged parts with a sterilized knife. Then, repot the plant into a new potting mix.

In contrast, underwatering causes drooping, dry, crispy, and yellowing leaves, gradually developing into black spots.

For that, water the Monstera immediately with tepid water or drench the pot for about 15-20 minutes and drain excess water.

Pro Tips- You can check soil moisture using a moisture meter or inspect soil moisture by inserting fingers or a stick 2-3 inches deep into the soil. Water only if the soil feels dry.

2. Improper Lighting

Other causes for leaves turning black in Monstera are sunburn and insufficient sunlight.

But, if you expose them to direct scorching sunlight, their leaves turn brown and black.

So you can correct the sunburn by readjusting the plant to shades, drawing a curtain in the window, or relocating to an east-facing window.

Similarly, low light intensity causes loss in chlorophyll pigments resulting in the yellow color of leaves.

It causes reduced photosynthesis and hampers the whole physiological process of plants. Thus, to mark the sign of stress, Monstera leaves turn black.

To correct the lighting effect, install a grow light and provide the plant with 1-2 hours of morning and afternoon rays.

Pro Tip- Rotate the plant once a week to obtain balanced growth.

3. Fertilizing Issues

Monstera shows their need for feeding or excessive fertilizer use through black leaf spots, which you should analyze immediately.

Nutritional deficiencies in Monstera result in regressive growth and the appearance of black spots, making the plant weak and easily vulnerable to disease and pest attack.

 Immediately fix the condition by fertilizing your plant with organic fertilizer or NPK of ratio 3-1-2

However, ensure not to overfertilize them as it causes excessive salt accumulation causing burning and blackening of leaves.

Wash off excessive fertilizer by drenching the pot in a pool of water for about half an hour, and go for repotting if the soil is beyond cure.

4. Temperature Stress

The ideal temperature for Monstera is between 60-80°F. Temperature above or below the range and fluctuating temperature causes Monstera leaves to turn black.

High temperature causes rapid moisture loss and drying of leaves resulting in a black spot.

So balance the high temperature by misting the leaves regularly and bringing the plant indoors in case the plant is outdoors.

So better to use a frost blanket, a heating mat under the pot and avoid drafty places, and heating and cooling vents like heaters, radiators, etc.

You can also add mulch to prevent temperature loss from soil and provide insulation to the Monstera plant.

5. Unfavorable Humidity

Monstera loves high humidity, between 60-70%, as a tropical plant.

Since low humidity causes high transpiration in Monstera, forcing the leaves to turn black.

So, maintain the humidity around the plant using an electric humidifier or grouping the plant together to boost the moisture.

You can also mist the Monstera every 3-4 days or place pebble trays below the pot for continuous moisture.

However, do not let the humidity go beyond the range as it increases the chance of mold formation and fungal growth, turning leaves yellow and black. 

6. Pests and Disease Infestation

Another reason Monstera leaves turn black is the common pests hosting on it, like white flies, scales, thrips, spider mites, aphids, and fungus gnats.

You can identify their existence by looking at the discolored leaves, black spots under the leaves, and yellow larvae on the top.

Also, spray the plant with insecticidal soap or neem oil if the infestation is beyond control.

Meanwhile, black spots appear when your Monstera is affected by diseases like bacterial leaf spots, anthracnose, and root and stem rot, usually led by soggy soil.

So better to snip off the leaves with black spots as soon as you notice them, as they are contagious.

And treat the affected Monstera with a copper-based fungicide and repot the Monstera to remove all brown, mushy roots.

7. Wrong Soil Mix

Toxins in the soil, like lead, petroleum products, radon, arsenic, creosote, etc., are harmful to Monstera.

These toxins harm Monstera’s root, nutrition absorption, and overall physiological functioning. As a result, its leaves turn black.

Also, a soil pH of the 5.5-7 range is essential in the nutrition absorption and growth of the Monstera.

So better to use a well-draining, nutrient-rich soil mix and add coffee grounds, cottonseed meal, and pine bark to maintain the pH.

Should I Remove the Black Leaves?

You generally do not have to remove the black leaves as the black spot does not spread. However, you can always bisect the affected parts.

Moreover, pruning your Monstera is a way to enhance new growth because the damaged part of the leaves has already lost its vitality.

And will only be a hindrance to the entire plant’s growth. Thus, it is better to remove the affected parts while pruning Monstera.

Use a sterilized scissor or gardening shears to snip off black, yellow, and damaged leaves of Monstera near the stem base.

Also, cut off scraggly and awkward-looking branches when pruning off the Monstera.

Prune the Monstera leaves during the spring and summer as they are actively growing.

FAQs About Monstera Leaves

What does root rot look like on Monstera?

Monstera suffering from root rot problem shows stunted growth, a fishy smell nearby the plant roots, mushy stem with dark brown to black spots on the lower leaves.

Meanwhile, the roots turn reddish brown over time.

What does a dehydrated Monstera look like?

Dehydrated Monstera gives a droopy look where the leaves dry out and turn brittle and crispy with brown to black spots on the leaves.