The most common causes for black spots and edges on Monstera Deliciosa include too much or too little water, sunburn, low humidity, improper fertilization, diseases, pests, or unsuitable soil. This blog explains the following topics about Monstera leaves turning black.
- How to notice Monstera leaves turning black
- Causes of Monstera leaves turning black
- Why new Monstera leaves turn black before unfolding
- How to fix Monstera plants if their leaves are turning black
How to Notice Monstera Leaves Turning Black
Seeing your Monstera Deliciosa’s beautiful green leaves turn black can be quite disheartening.
But don’t worry; you can save the plant if you know what makes its leaves black and how you can help it produce green leaves again.
The first key point here is to diagnose the root cause as soon as you notice the leaves turning black.
You may want to look out for: dry, crumbly, blackened edges, black spots, or blackening foliage. These signs are easily noticeable, and they make your Monstera plant quite unsightly to look at.
Causes of Black Monstera Leaves
Monstera leaves can start turning black due to multiple reasons. You have to identify what’s wrong to stop them from turning black.
Here is a list of causes that can make your plant’s leaves turn black.
Overwatering
Overwatering is when you provide too much water to your plant in one go or don’t wait for the top few inches of the soil to dry before the next watering session.
Your plant also suffers damage from excess water if the pot doesn’t have proper drainage holes or the soil isn’t well-draining.
An overwatered Monstera plant features musty soil and mushy stems, leaves, and roots. Overwatering can cause new Monstera leaves to turn black even before they unfurl.
Lack of Water
Under-watering is when you let the soil completely dry out between the watering sessions. It can lead to drooping, crispy, dry, and yellowing leaves that later develop black spots.
Both excess and lack of water can make Monstera leaves turn black. Therefore, it’s essential to strike a balance when watering your plant.
Fixing a watering schedule may not be a good idea because the amount of water your Monstera requires can change over weeks or months, depending on various environmental factors.
The best way to ensure your plant is getting adequate water is to keep a check on the soil. Stick a thumb into the soil; if the top few inches feel dry, your plant is ready for a drink.
Problems With The Soil
Does your soil absorb water with difficulty? Do puddles of water remain on the soil’s surface long after you water the plant?
Does your soil have a high clay content? If you answered yes to any of these questions, the soil you are using isn’t suitable for your Monstera plants.
Some plants can grow in any type of soil, while others require a certain kind of soil to thrive. Monstera plants are aroids that require a well-draining soil mix to avoid root rot.
Moreover, the potting soil must be well-aerated to help fast-growing Monstera roots breathe easily.
Another vital point to remember is that your plant may not get enough water if the soil becomes hydrophobic. Hydrophobic soil cannot soak water properly; the water you pour eventually drains from the pot.
Cold Shock
Tropical plants like Monstera grow well in climates similar to their natural habitat.
More precisely, warm and humid environments are the best for Monstera plants. Too cold or too hot and dry conditions may negatively affect their health and growth.
Monstera plants can quickly go into shock when exposed to freezing temperatures. It usually happens when they are kept outside or near drafty windows and doors in chilly temperatures.
Direct Sunlight
Monstera plants prefer lots of bright, indirect sunlight because they originate from tropical regions.
Their leaves burn and develop black spots if you keep them under direct sunlight without shade, near a bright window, or close to a direct heat source.
Sudden temperature changes can also rupture the leaf tissue, leading to black or brown spots on the leaves. This usually happens when the plant is moved from a warm, humid environment to a cooler, dry one.
Lack of Humidity
Humidity is another important factor to consider when diagnosing why your Monstera leaves are turning black. Since Monstera is a tropical plant, it is accustomed to high humidity levels. Hence, low humidity can cause the leaves to dry out, become crispy, and develop black or brown spots.
Excess or Lack of Fertilization
Fertilizing a plant is important for its growth and development, but excess fertilizer can cause significant damage.
When a plant is over-fertilized, excess nutrients build up in the soil and burn the leaves, turning them brown or black.
Similarly, degenerative growth due to inadequate fertilizer can also lead to the growth of black and yellow patches on the leaves. This is because nutritional deficiency makes your plant vulnerable to pest attacks and diseases.
How frequently you should fertilize depends on the type of fertilizer you plan to use, the size of the plant, and the stage of its growth.
Generally, it is recommended to fertilize a Monstera every 2-4 weeks during the growing season (spring and summer) with a balanced, liquid fertilizer.
In the fall and winter, it is best to reduce the frequency of fertilization or stop it altogether. This is because the plant’s growth naturally slows down during these months.
Don’t fertilize a plant that is already showing signs of stress or damage, and ensure that the soil is well-draining to avoid over-fertilization.
Follow the instructions on the fertilizer package, as different products may have different recommendations.
Fungal and Bacterial Diseases
Fungal and bacterial diseases can also cause a plant’s leaves to turn black. In fact, some of them can even kill your plant quickly if not caught in time.
Root rot is one such disease that commonly affects Monstera plants and leads to plant stress.
Root Rot
Root rot usually occurs due to overwatering, a soil mix that doesn’t drain well, or a pot that doesn’t allow proper drainage. Roots sitting in the water for a long time are likely to develop fungi and bacteria.
Want to check if your Monstera is suffering from root rot? Gently free it from the planter and assess the roots. If the roots seem black and mushy, your plant is a clear target of root rot.
Pest Infestation
Pest infestation is a nightmare for houseplant owners and can affect plant growth. Pests suck on the sap of the leaves and stems, leaving brown or yellow spots that eventually turn black.
The most common pests that attack Monstera plants include spider mites, thrips, and mealy bugs.
Some insects are hard to notice with the naked eye, so they can swiftly spread throughout the plant long before you know there is a problem.
Spider mites
Spider mites look like tiny black dots, usually found on the underside of the leaves. They tend to leave fine webbing on the leaves and stems.
Mealybugs
Small white cottony masses can signify mealybugs infestation on leaves, stem, and roots. Other signs of their presence are sticky honeydew and black sooty mold on the leaves.
Thrips
Thrips are tiny, leaf-sucking flies that target a plant’s water supply. They usually look like tiny, black or brown fecal spots on the leaves. Thrip infestations can make the leaves on Monstera plants look discolored and curled.
Note: A diseased or pest-infested Monstera plant can infect other plants too. Make sure you isolate the affected plant and clean the pruning shears with a disinfectant before using them again. Dispose of the diseased or damaged leaves properly rather than leaving them in the soil.
How Do I Fix Black Monstera Leaves?
If your Monstera leaves are turning black, you need to look closely at its environment and care routine to diagnose the problem and take appropriate measures to fix it.
Here are some solutions you can consider based on the root cause of blackening Monstera leaves.
When Overwatering Is The Problem
If your Monstera leaves are turning black due to overwatering, stop watering the plant as much. Always wait until the top few inches of the soil dry out completely before watering again. While watering, ensure that the water just goes to the soil and not to the leaves.
If the roots of your Monstera have started rotting due to excess water, the best solution is to repot the plant in fresh soil. Remove the Monstera from its pot, wash the plant’s roots, and gently cut the damaged roots with clean gardening shears.
Then, repot your Monstera using fresh, well-draining soil. Make sure the container has proper drainage holes at the bottom to let excess water out.
Note: Don’t forget to remove any black or dead leaves from the plant, as they can harbor disease and pests.
When Underwatering Is The Problem
The soil will look completely dried out if your Monstera plant is suffering from a lack of water.
In that case, immediately water the plant with tepid water or drench the pot for almost 15 to 20 minutes, flushing out the excess water.
Wait for the top few inches of the soil to dry before the next watering session.
When Soil Is The Problem
If your soil doesn’t drain out excess water or stops absorbing water, you must repot your plant in a well-draining potting soil as soon as possible.
A well-draining soil mix typically consists of peat moss, orchid bark, and perlite. This will help ensure that your Monstera absorbs enough water and the excess water successfully drains away from the roots.
When Extreme Temperatures Are the Problem
You must find a way to keep your plant warm when it gets too cold in your region. Bring the plant inside if you keep it outside, or move it away if it’s kept near a draft window.
You can also cover it with a blanket at night or move it close to a heat source (not too close because direct heat can burn the leaves).
If the Sun shines too bright in your region, put your plant in an area where the light doesn’t fall directly on the leaves.
Prolonged exposure to direct Sun can scorch your leaves, leaving them with crisp edges and black burn marks.
Move the pot to a shaded area if you are keeping it outside. Add a curtain if you keep the pot near a window that gets direct light.
When Low Humidity Is The Problem
If your Monstera leaves are turning black because of low humidity, you can try the following techniques to increase the humidity level around the plant.
- Regularly mist the leaves of the plant with a spray bottle.
- Use a humidifier to increase the humidity in the room where your Monstera is kept.
- Group your Monstera with other plants to increase the humidity around them.
- Fill a shallow tray with pebbles and water, and place the plant’s pot on the top. The humidity level around the plant will increase as the water evaporates.
- Keep your plants away from sources of dry air, such as air conditioners or heating vents.
- Be careful not to overwater the plant but ensure its soil remains moist.
When Overfertilization Is The Problem
If your Monstera leaves are turning black due to fertilizer burn, the first step is to flush the soil with water to remove as much of the excess fertilizer as possible.
If you have used a removable fertilizer, such as pellets or sticks, take them out.
Next, prune any black or discolored leaves to help the plant direct its energy on new growth, monitor the plant closely, and continue to provide proper care.
If the leaves still keep turning black, you may have to repot the plant with fresh, sterile soil.
When Pests Attack Is The Problem – Neem Oil to The Rescue
If you suspect a pest attack, first identify the type of pest causing the damage. Once you know the type of pest you are dealing with, you can take appropriate actions to remove them.
An effective way to get rid of most pests is to wipe the leaves with a damp cloth and spray a solution of water and mild dish soap on the affected areas of the plant.
You can also use neem oil, horticultural oil, or insecticidal soap to control pests.
Note: Prevention is always better than cure. You should regularly inspect the plant for pests and take appropriate measures as soon as you notice any signs of infestation.
Should I Cut Off Black Leaves From My Monstera Plants?
The answer to this question is yes.
Discoloration usually indicates that the leaf is dead or dying. Cutting them off will allow your plant to direct its energy on new growth, make it look better, and prevent the spread of the problem.
However, cutting off the black leaves doesn’t make your Monstera healthy again. If you don’t address the actual problem causing the black leaves, new leaves will also start turning black.
Hence, more important than cutting off the black leaves is identifying and addressing the root cause of the problem, whether it be pests, disease, improper watering, or anything else.
When pruning the black leaves, use clean, sharp scissors or pruners to prevent further damage to your Monstera plant. Follow these steps:
- Locate the black or discolored leaves on the plant.
- Carefully trim the stem as close to the base of the black leaf as possible. Be careful not to damage the surrounding leaves or stem.
- Discard the removed leaves immediately rather than leaving them in the soil. This will prevent the pest or disease from spreading.
- Check the remaining leaves for any signs of pests or disease and take the necessary actions.
- Clean your pruners or scissors with rubbing alcohol or a solution of water and mild soap before and after pruning to prevent bacteria from spreading.
Frequently Asked Questions
Why Are The Edges Of My Monstera Leaves Turning Black?
The edges of Monstera leaves turning black can result from several factors. Some of them are as follows:
- Cold Shock: Such a big plant like Monstera requires high temperatures to warm up. If the temperature falls below 55°F, the leaf edges may turn black as a result of cold damage.
- Prolonged Exposure to Light: The leaf edges may turn black if the plant gets too much direct sunlight.
- Environmental stress: A sudden change in temperature, humidity, or light can cause stress on the plant, which can cause the leaf edges to turn black.
- Pests: Pests like spider mites, mealybugs, and scale insects can also cause the edges of the leaves to turn black by feeding on the plant’s sap.
- Disease: Certain fungal or bacterial diseases can also cause the leaf edges to turn black.
It’s important to identify what’s causing the leaves to turn black. If you suspect disease or pests, take appropriate action to eliminate them.
If the signs indicate a nutritional deficiency, consider fertilizing with a balanced fertilizer. If you have exposed the plant to direct light, move it to a location where it receives the right amount of bright, indirect light and temperature.
Can Monstera Plants Recover From Black Spots?
Monstera plants can recover from black spots, depending on the root cause of the problem and the extent of the damage.
Black spots on Monstera leaves are mostly caused by fungal disease from overwatering and pest damage.
If the black spots are caused by a minor issue, you can help the plant recover with proper care and treatment. However, the plant may not recover completely if the problem gets out of control.
It is essential to take appropriate measures to eliminate the underlying issue and prevent it from spreading to other parts of the plant.
Why Are My Monstera’s Leaves Turning Yellow and Black?
Black and yellow leaves can look even more unattractive than leaves with black spots, but they are easier to notice. You can easily spot them before the underlying problem gets out of hand.
Improper watering frequency or technique is the most common cause of discoloration, but the plant’s placement in your home can also be the culprit. Observe if your plant is getting enough bright, indirect sunlight or not.
Why Are My Monstera’s Leaves Turning Black Before Unfurling?
Sometimes, new Monstera leaves can turn black even before they have uncurled all the way. Although it’s a pretty sad and disappointing sight for the plant owners, it doesn’t mean your plant will die.
It usually happens when your plant is getting too much or too less water, and you can address the issue to help your plant grow new, green leaves.
My name is Daniel Elrod, and I have been houseplant love ever since I was 17. I love how much joy they bring to any room in the home. I’ve always been amazed at how a few pots of flowing leaves can turn a drab and sterile office into an inviting place where people love to work at.
