Are you looking to tackle those pesky black spots on Monstera leaves head-on?
As a seasoned horticulturist and plant aficionado, I’ve battled this issue personally and invested endless hours researching to conquer it.
This action-packed post will explore the factors causing those dreaded black spots on Monstera leaves.
We’ll also share kick-butt preventative measures and powerful treatments to annihilate this problem.
So, strap in and prepare to discover how to identify, prevent, and obliterate the usual suspects behind the unsightly black spots on your monstera leave
First things first;
Why does my monstera have black spots?
Black spots on a Monstera plant can be caused by a few factors. Overwatering can lead to root rot, which manifests as black spots on leaves. Fungal or bacterial infections can also cause black spots. Physical damage or excessive sunlight can also cause leaf burns, appearing as black spots.
Monstera adansonii black spots
Monstera adansonii can develop black spots due to overwatering, root rot, or infections from bacteria or fungi. Inadequate light or extreme temperature fluctuations may also contribute to the issue. Ensure proper care by regulating water, light, and temperature, and monitor the plant for signs of improvement.
Monstera deliciosa black spots
Monstera deliciosa may develop black spots due to anthracnose, a fungal disease caused by Colletotrichum species. This issue often arises in humid conditions or with overwatering. Another cause is bacterial leaf spot, resulting from pathogens like Xanthomonas or Pseudomonas. Prevent these issues by avoiding overhead watering, providing good air circulation, and removing infected leaves to prevent the spread of pathogens.
Monstera deliciosa turning black
Monstera deliciosa may turn black due to root rot, which occurs when the plant is overwatered or has poor drainage, leading to oxygen-deprived roots. This condition fosters fungal or bacterial growth, causing the plant’s roots and leaves to turn black. To prevent root rot, use well-draining soil, avoid overwatering, and ensure the plant is in a container with drainage holes to prevent waterlogged conditions.
Causes of monstera leaves black spots
1. Over Watering
Over-watering can cause black spots on Monstera leaves due to root rot and nutrient deficiency.
The soil can get too wet if you give your Monstera plant too much water. This might make the roots start to rot. Root rot happens when there is too much water around the roots and they cannot breathe.
As the roots die, they can’t absorb water or nutrients from the soil, making the leaves turn black or develop black spots.
If a plant can’t transport water and nutrients to its leaves, the leaves will get dry and die.
Over-watering also creates a conducive environment for harmful bacteria and fungi growth. These microorganisms attack the plant’s tissues, causing them to break down and turn black.
Other signs of Overwatered Monstera
- • Wilting leaves
- • Drooping stems
- • Browning of monstera leaf tips and edges
- • Foul smell from soil
- • Excessively yellow leaves
- • Mushy stems or roots
Solution
- Allow the soil is dry out between waterings.
- Use a well-draining potting mix
- Buy a pot with drainage holes to allow excess water to escape.
2. Under Watering
Underwatering can cause black spots on Monstera plant leaves due to several reasons. When you don’t give a Monstera plant enough water, it will be stressed and this can cause black spots to appear on the leaves.
Here are some of the ways that underwatering can cause black spots on Monstera plant leaves:
Reduced Nutrient Uptake: When a Monstera plant is underwatered, its roots do not receive enough water and nutrients. This can cause black spots on monstera leaves because the plant cannot produce enough chlorophyll to maintain its green color.
Fungal Infections: Underwatering can also make the Monstera plant vulnerable to fungal infections. When a plant is dehydrated, its immune system weakens, making it more susceptible to fungal attacks. Fungal infections can cause black spots on Monstera plant leaves.
Insect Infestations: Underwatered Monstera plants can also attract insect infestations, such as spider mites and mealybugs. These insects can cause black spots on Monstera plant leaves by feeding on their tissues and disrupting their normal growth.
Symptoms of dry potting soil
- Soil feels dry and crumbly when touched
- Plants appear wilted, or leaves turn yellow
- Accumulation of salts in the soil
- Soil lacks organic matter, nutrients, and moisture
- Shallow roots
What to do:
- Removed damaged leaves.
- Water your Monstera slowly but deeply. This approach helps ensure no dry patches remain in the soil. Stop watering when the water starts flowing out of the drainage holes.
3. Unfavourable water quality
To ensure optimal nutrient uptake, use high-quality water for your Monstera. Poor water quality can affect the plant’s growth by altering the uptake of micronutrients
Acidic water can increase soil acidity, inhibiting the solubility of micronutrients such as iron. Conversely, high water pH levels can dilute the nutrients and reduce their concentration.
When the solubility of nutrients is reduced, it can cause deficiencies. This means there might not be enough nutrients available for the plant. This can cause the leaves to turn black or yellow, a condition called chlorosis.
What causes bad water quality?
Fluoride, a naturally occurring mineral, is a common factor that affects water quality. Water can also be contaminated by pesticides, arsenic and nitrate pollutants.
4. Sun Burn
Monstera plants do best in bright indirect. And they can have problems if exposed to direct sunlight for too long.
These plants come from tropical areas, growing under canopies that keep the light filtered. To keep them healthy, we must ensure they have similar conditions indoors.
The best way to provide lighting for your Monstera plant is to place it near a window with sheer curtains. This will allow the plant to receive the right light to grow healthily.
If your Monstera plant has been in the sun for too long, the leaves may turn black and the effect is irreversible.
Symptoms of sunburned Monstera leaves;
- Large black spots on the leaf surface
- A mixture of yellow and black patches that become crispy and eventually die off.
How to deal with sunburned leaves on your Monstera plant;
- Cut away any badly damaged leaves to promote new growth.
- If your plant is near a south-facing window, you should consider moving it to a west- or east-facing window
- Leave about 5 feet between the plant and the south-facing window.
- Cover the window with sheer curtains to filter the light.
5. Low Humidity
Monstera is a tropical plant that thrives in high-humidity environments. The humidity around your Monstera should be above 50 percent for optimal growth.
Since Monstera leaves are big, the plant loses water quickly when the air around it is not humid.
Symptoms of low humidity
Black leaf margins and drooping leaves. If you do not stop these symptoms, they will get worse. More parts of the leaves may turn black, and the plant may die.
How to Raise Humidity to Optimum Levels
- Cover the monstera plant with a large plastic bag or humidification pouch.
- Group plants together to create a “microclimate” but avoid overcrowding.
- Keep monstera near the kitchen for increased humidity.
- Mist plants regularly with distilled water and spray both sides of the leaves.
- Move away from direct light/heat sources to retain humidity.
- Run an essential oil diffuser
- Use a humidifier with adjustable settings
- Boil water for additional moisture in the air
- Use peat moss-based potting mix.
6. High Humidity
While low humidity can cause black or brown leaf margins and drops, high humidity can also lead to leaf problems.
When the air is too humid, it causes more water to collect on the surface of leaves. This makes them vulnerable to fungal or bacterial diseases.
One of the most common diseases caused by high humidity in Monstera plants is the black leaf spot (Cercospora leaf spot).
This disease causes small black or brown spots to appear on the leaves. The spots can grow and cover the whole leaf, causing it to turn black and die.
Black leaf spot is caused by a fungus called Cercospora. This type of fungus grows well in warm, humid conditions.
The fungus first attacks the leaves of the Monstera plant. Then it spreads to other parts of the plant and causes severe damage.
To prevent black leaf spots in Monstera plants, maintain proper humidity levels. While Monstera plants prefer humidity above 40%, excessively high humidity above 80% can be detrimental.
Solution
- Prune affected leaves and treat the plant with a fungicide to prevent the spread of the disease.
- Improve the plant’s air circulation by opening windows or using a fan.
- Avoid overwatering
7. Improper Fertilization
Monstera plants need to get the right nutrition to grow healthy. Black spots may appear on their leaves if they don’t get enough or the wrong fertilizer.
Using too much fertilizer can make salts build up in the soil. This will cause plants to take in too much water and nutrients, creating black spots on the leaves.
Monsteras need certain nutrients like iron to grow. If they don’t get enough of these, the leaves can turn yellow or have black spots. Follow the recommended fertilization schedule and dosage for Monstera plants to avoid nutrient imbalances that can cause black spots.
Pro tip: Before applying, dilute the liquid fertilizer with equal water.
How to Deal with Improper Fertilization
- Rinse the plant thoroughly in running tap water 3 or 4 times until all traces of salt are gone.
- Reduce your fertilization during the autumn and winter seasons.
- Refrain from fertilizing until the plant shows signs of revived growth.
- For plants that have wilted and ceased to grow, a new potting mix can be just the remedy they need. Transplanting them into fresh soil will help revive their vitality.
8. Disease Attack
Bacterial leaf spot is a common disease caused by the bacteria Xanthomonas campestris. It is characterized by water-soaked spots on the leaves, which eventually turn brown or black.
The spots may also have a yellow halo around them. As the disease progresses, the leaves may become distorted or drop off.
Other symptoms of Bacterial leaf spot
- Wilting and yellowing of leaves
- Stunted growth
- Leaves may become distorted in shape or form
- Dark spots and patches on the leaves, sometimes with a yellow halo around them
- Lesions on stems
- Leaf drop or defoliation
Prevention and Control Strategies:
- Avoid overhead watering and keep the foliage dry.
Prune infected leaves
- Use pure neem oil
9. Incorrect Temperature
Monsteras are naturally adapted to tropical environments with a warm and humid climates.
So, any significant change in temperature can have adverse effects on the plant’s health
Even though the plant thrives in warm temperatures, excessive heat can be harmful. Sustained exposure to temperatures above 100 degrees Fahrenheit can cause damage to the plant and its leaves.
Conversely, cold weather can also lead to the leaves turning black.
When growing Monstera plants indoors, keep them away from sources of cold air such as AC units or drafts.
Exposure to cold drafts can cause black spots to appear on the leaves. If left unchecked, prolonged exposure can lead to severe damage, causing the leaves to wilt and die off.
What to do
- Carefully cut away leaves that have sustained more than 50 percent tissue damage.
- Relocate the plant to a room between 65 and 90 degrees Fahrenheit.
- Do not put the plant anywhere near an AC or refrigerator.
Incorrect Potting Mix
Poor drainage could result in waterlogged soil if the incorrect potting mix is used. This can cause black spots or complete blackening of the monstera leaves.
The issue usually occurs during the early stages due to much organic matter in the soil, making it difficult for oxygen to reach roots.
To make matters worse, stagnant water increases acidity levels in the soil, leading to an overall reduction in pH level which is essential for healthy growth.
Fortunately, you can avoid all these using the correct organic retainers, such as moss chunks, perlite and coconut fiber, etc.
Also, avoid fertilizers made up of slow-release nitrogen sources.
Pests
Monstera plants are relatively resistant to indoor bugs. However, they can still be attacked by common pests such as spider mites, scale, thrips, and fungus gnats.
These pests are attracted to monstera because they are phytophagous insects that feed on the sap and tissue of the plant.
Pests like scale can be found in the leaf joints and stem, while the larvae of adult fungus gnats can feed on the roots, and thrips can suck moisture from the plant.
If monstera is attacked by pests, it can be destroyed, and in the worst-case scenario, it can kill the plant.
Prevention and control measures
- Wipe the leaves with 70% rubbing alcohol
- Use horticultural soap
- Get pure neem oil
How to control the spread
- Isolate the plant
- Buy predatory mites and ladybugs as biological control,
- Use mosquito bits to destroy fungus gnats
- Get yellow sticky gnat traps, which are cheap, nontoxic, and effective.
- Provide good growing conditions for the plant
Certainly! Here’s a revised version focusing solely on the symptoms of dark spots on Monstera leaves:
Symptoms of Dark Spots on Monstera Leaves
Leaves Turning Black on Edges
- The edges of the leaves exhibit a distinct black coloration.
New Monstera Leaves Turning Black
- Newly grown leaves show blackening, often starting from the tips or edges.
Leaves Turning Black Before Unfurling
- Leaves display black spots or areas before they fully open and expand.
Leaves Turning Black & Yellow
- A combination of black and yellow discoloration appears on the leaves, often in patches or along the veins.
When & How To Remove Leaves with Black Spots
Generally speaking, leaves with black spots will not heal themselves. As long as your plant has a couple other fully open and healthy leaves, you can remove the leaf with the black spots or edges.
If the whole leaf has turned black, you will want to remove it immediately to prevent it from spreading to your whole plant.
Use a good set of pruning shears like these to cut off any blackened leaves. Don’t forget to sanitize your shears before using them on any other plant!
General Care to Avoid Monstera Leaves Turning Black
Position
Proper positioning of your Monstera is crucial. It needs sufficient space, appropriate lighting, and a stable environment to thrive.
- Space and Light: Mature Monsteras can reach impressive heights, with leaves spanning up to 3 feet. Place your plant near an east-facing window for optimal indirect light. For south- or west-facing windows, use sheer curtains to diffuse the light and avoid direct sun exposure. Keep your Monstera at least 2-4 feet away from direct light sources to prevent foliage damage.
- Feng Shui Approach: This can also be beneficial for positioning your Monstera, ensuring a harmonious balance in the room.
Temperature
Monsteras prefer a warm, humid environment, with ideal temperatures ranging between 65-85℉ (18-29°C).
- Regulating Temperature: In hotter months, shield your plant from direct sunlight and provide extra warmth during colder seasons. Keep it away from air conditioners and heaters to avoid temperature extremes.
- Signs of Temperature Stress: Look out for yellowing or curled leaves, black or brown spots, slow growth, or leaf drop, which can indicate temperature issues.
Humidity
Maintaining the right humidity level, ideally between 60% and 80%, is key.
- Monitoring Humidity: Use a hygrometer to check humidity levels. Increase humidity with a humidifier or by misting your plant. Grouping plants together can also create a beneficial microclimate.
- Humid Environment: In naturally humid climates, additional humidity measures might not be necessary.
Potting and Repotting
Choose the right pot and soil mix for your Monstera.
- Pot Selection: Use a pot 1-2 inches larger than the current one, with drainage holes.
- Soil Mix: Opt for a well-draining, nutrient-rich mix containing peat moss, perlite, and some compost.
- Repotting Process: Repot young Monsteras annually and mature ones every 2-3 years, preferably in spring or early summer. Remove damaged roots before repotting.
Light
Monsteras need bright, indirect light to mimic their natural tropical habitat.
- Light Conditions: Avoid direct sunlight to prevent leaf scorching. If the plant shows signs of leggy growth or small leaves, it may need more light.
- Lighting Tips: Place your Monstera near an east or west-facing window and rotate it periodically for even light exposure. Use grow lights if natural light is insufficient.
Watering
Watering frequency depends on environmental factors.
- Watering Schedule: Generally, water once every 1-2 weeks, allowing the top inch of soil to dry out between waterings. Use the “soak and drain” method for thorough watering.
- Monitoring Water Needs: Adjust watering based on the season and check the soil moisture before watering.
Fertilizer
Select a suitable fertilizer and apply it correctly.
- Fertilizer Type: Use a balanced, slow-release 20-20-20 N-P-K ratio fertilizer.
- Application: Fertilize every 4-6 weeks during the growing season and adjust the amount according to your plant’s needs.
Soil
The right soil mix is vital for Monstera health.
- Soil Composition: Use a well-draining mix with peat moss, perlite or orchid bark, and organic matter.
- Soil pH: Maintain a slightly acidic to neutral pH (5.5 to 7.0) for optimal nutrient absorption.
FAQs
Should I cut black leaves off Monstera?
Yes, remove black leaves from Monstera plants as they suggest issues like root rot or infections. Prune these leaves to prevent spread and encourage healthy growth. Use sterilized shears for trimming. Proper disposal and addressing the root cause are crucial to avoid recurrence.
What are tiny black dots on Monstera?
Tiny black dots on Monstera leaves are often a sign of pest infestation. Thrips, spider mites, or scale insects can leave small, dark-colored droppings or excrement on leaf surfaces. Inspect your plant closely for the presence of these pests, and treat them with insecticidal soap, neem oil, or a suitable pesticide. Additionally, maintain proper care practices to minimize the likelihood of future infestations.
How to fix black spots on Monstera?
First identify the cause, such as overwatering, pests, or diseases. For overwatering, adjust your watering schedule and ensure proper drainage. For pests, treat the plant with insecticidal soap or neem oil. If it’s a fungal or bacterial infection, remove affected leaves, apply a suitable fungicide or bactericide, and improve air circulation. Regularly monitor your plant and maintain proper care practices to prevent future black spots.
Conclusion
Choosing the right care approach to save a monster with black spots can be confounding.
But with high-quality soil, adequate lighting, and regular watering, your plant should stay happy and healthy! What’s more, try to increase humidity in your indoor environment.
Use humidifiers or incorporate leaf mistings if it helps.
Most importantly, remain patient when dealing with this issue since, as you might have noted, solutions don’t happen overnight – they take time to unfold.
This also applies when it comes to repairs and the healing process. Eventually, these interventions will yield amazing results when done correctly.
