Black leaves on any kind of plant are never a good sign when it comes to their health. The severity of the damage it poses to the plant is always dependent on what’s causing the issue.
If you’re a plant enthusiast or experienced gardener, you’ve likely come across this problem at least once or twice. Luckily, black leaves and spots can be remedied and prevented with a few quick and simple steps.
If you’re worried or currently struggling with this problem with your Monstera plant, we’ve got you covered. On that note, let’s take a look at the causes and effects of Monstera black leaves, as well as how to fix them.
What Are the Effects of Black Spots on a Monstera?
Black spots in a plant’s leaves often result in the reduction of its photosynthesis and a decline in productivity. Its presence has no particular advantages to a plant, so as soon as you spot them in your Monstera, it’s time to do some investigating.
Just like the causes, the effects of the black spots can differ depending on what’s causing them. These are some of the concerns you need to take note of if the black spots are left unattended:
- Disruption in photosynthetic processes
- Further dehydration
- Nutrient deficiencies
- Root rotting
- Stunted growth
- Infestation of pests and diseases
- The plant’s death
The key here is to act as quickly as possible once you see black spots appearing on your plant. It may not always be as serious as it appears to be, but it’s better to be sure to prevent worse-case scenarios.
If by any chance, it results in an infestation and you have other plants in the area, their health will also be at risk.
What Causes Black Spots on a Monstera?
There are many health concerns that can trigger black spots on a Monstera plant. Some of them are caused by simple issues that are easily fixable, while others may need further treatment.
In most cases, it’s due to the lack or excessiveness of a certain plant TLC step. That’s why it’s crucial to pay attention to your Monstera’s needs to ensure you’re giving the right and proper amount of care.
Black spots on a Monstera plant are often caused by the following:
- Improper watering conditions
- Prolonged exposure to extreme temperatures
- Inefficient lighting setups
- Lack of humidity
- Effects of pest infestations and diseases
Let’s go into further detail on these specific causes to understand your Monstera plant’s condition better.
1 – Improper Watering Conditions
Giving your Monstera too much or too little water is detrimental to its health and can result in a lot of health issues.
One of the common symptoms you might see from improper watering conditions is the appearance of black spots.
Plant owners can sometimes be too eager to care for the plants that they tend to give them too much water. Other than black spots, overwatering can be detected with these signs:
- The Monstera starts to develop yellow leaves and stems
- Its soil appears and feels to always be damp and soggy
- Its stems and leaves can have a soft and mushy texture
Overwatering can also lead to eventual fungal infections and root rot. The more soaked the Monstera’s soil, the less oxygen its roots can absorb for plant functions.
Even though Monsteras can survive a few skips in their regular watering routine, too much can lead to dehydration.
Apart from black spots, its leaves can also have a light brown color and crispy-looking exterior, especially on the edges.
If your Monstera is root-bound, its soil tends to dry out faster because there’s less space for holding water.
Having the roots of a Monstera popping out of the pot is usually a sign that it needs repotting so it can grow more and hold water better.
2 – Prolonged Exposure to Extreme Temperatures
Monstera plants thrive in a rainforest-like environment with a warm and humid temperature. Cold and extremely hot temperatures are bad news for this subtropical plant.
If the plant is exposed to cold temperatures for too long, it can easily experience a cold shock. A cold shock may not just cause black spots but also turn the entirety of the leaves black.
As much as Monsteras are weaker to cold temperatures, an excessively hot environment poses just as much threat.
If the plant is exposed to too much heat it can handle, its leaves can eventually turn black.
3 – Inefficient Lighting Setups
Black spots in a Monstera’s leaves can also be a sign of stress from inefficient lighting setups.
It can either be caused by sunburn due to direct exposure to scorching sunlight or a stress reaction from reduced photosynthesis activity due to low light intensities.
While a Monstera plant enjoys being bathed in bright lights, extreme conditions can cause irreparable damage to its leaves. In the case of scorching or sunburn, some of its leaves may fall off completely.
As for low-intensity lights, your Monstera can lose chlorophyll pigments, which will cause the color of its leaves to turn yellow. Since it also reduces the plant’s capability for photosynthesis, its physiological processes are also affected.
4 – Lack of Humidity
Since Monstera plants are used to a subtropical environment, they can endure high levels of humidity. However, the same can’t be said if there’s not enough humidity in your plant’s environment.
While it’s common to mistake underwatering for low humidity, these are two different conditions. The key difference with lack of humidity is that the plant’s leaves dry up mostly on the tips rather than the sides or edges.
Low humidity for Monsteras can also cause bacterial and fungal infections. This can result in black or brown spots in the plant’s leaves.
5 – Effects of Pest Infestations and Diseases
Pest infestations and plant diseases are two of the most menacing culprits of black spots on a Monstera. Not only can they be contagious, but also lethal if not acted upon immediately.
If your Monstera’s leaves are damaged due to pests and diseases, it’s better to trim off the leaves that are affected. The affected leaves won’t recover and can spread further if ignored.
Plant pests are annoying to deal with and can easily wreak havoc on your garden or houseplants. They nibble away at your Monstera’s leaves, roots, and organic matter in the soil.
The common pests you need to watch out for in Monstera plants include:
- Spider mites
- Fungus gnats
As soon as you spot these unwanted creatures, be sure to isolate your Monstera from other plants to avoid spreading.
Most plant diseases cause the leaves of a Monstera to eventually turn black or have black spots. More often than not, these diseases are caused by overwatering and improper soil mixes.
Here are the most notable diseases your Monstera can develop:
- Bacterial leaf spot
- Stem and root rot
- Eyespot disease
- Fungal leaf spot
Plant diseases are a bit tricky but not impossible to deal with. You just have to pay attention to the condition of your Monstera, so you can act accordingly.
How to Fix and Prevent Black Spots on a Monstera
Here’s some good news to plant lovers and beginners: Monstera plants have a high survivability rate and are easy to maintain! You just have to be consistent with the non-daily routines you have to follow.
The watering routine Monstera plants need is easy to follow and won’t cause too much stress. All you have to do is water the plant at least once every 1 to 2 weeks.
The key is to water your Monstera until it drips out of the pot’s drainage hole. It’s also ideal to check the soil before watering to make sure it’s completely dry before doing so.
Temperature and Humidity
The ideal temperature for a Monstera ranges from 65° to 85°F, with a humidity level of at least 40% or higher. Having a thermometer and hygrometer can also be handy to check and maintain the temps and humidity.
If your plant is showing any of the symptoms relating to temperature and humidity, adjust the conditions accordingly.
Monsteras love indirect bright light, but harsh sunlight can cause severe damage. The same goes for low-intensity lights.
If you’re keeping your plant outdoors, give it enough shade so it can still tolerate sunlight. If indoors, a bright indirect light source will suffice.
Pests and Diseases
When it comes to pests and diseases, the faster you act the better. It’s a good idea to check for pests once in a while, even without symptoms, as some insects can be a bit hard to see.
Neem oil is also an effective combatant to pests and fungal and bacterial diseases.
If your plant struggling with certain diseases, you can use fungicides such as:
- Cinnamon powder
- Baking soda and lukewarm water mix
- Apple cider and lukewarm water mix
Remember to isolate the plant as well and trim off any affected leaves.
Black leaves on a Monstera plant can be quite scary to look at, but it only takes a little effort to resolve it. The first thing you have to do is diagnose the situation so you can apply the correct solution.
The best way to avoid unwanted situations is to do occasional maintenance checks once in a while. A little effort in keeping the plant healthy goes a long way.
Monsteras are low-maintenance, but that doesn’t mean you have to slack off in caring for the plant. At the end of the day, a healthy plant will bring you less stress and more relaxation.
Growing up with a mom who filled her home (inside and out) with all sorts of plants, Lisa got her start in gardening at a young age. Living now on her own with a home and yard full of plants (including an indoor greenhouse), she shares all the gardening tips she’s gained over the years.