Monstera rank among the most popular houseplants because of their unique leaves. In fact, many Monstera plants are very expensive because they are hard to find and very much sought after.
While the plant is fairly easy to care for, it can encounter some problems along the way. If you suddenly find that your Monstera leaves have brown spots it is important to figure out what’s happening and fix the issue immediately.
Why does your monstera leaves have brown spots? Often, brown spots on Monstera leaves is caused by overwatering. But it can be caused by too much light, disease, pests, temperature issues, excess fertilizer and underwatering.
This means it is important to identify the root cause first before you’re able to start treatment.
Reasons Why Monstera Leaves have Brown Spots
Monstera are native to the rainforests of Central America. As such, they thrive in a very specific tropical, humid, damp environment that is not easy to replicate at home.
So, the plant can develop different issues including brown spots on its leaves if it does not get the same living conditions that it is used to.
Below, I’ll go through the different causes of why monstera leaves turn brown. This will let you eliminate them one by one until you narrow down which one is the issue for your plant.
Overwatering is the most dangerous thing you can do to any houseplant. And this includes Monstera plants because too much water is the #1 cause of indoor plant death.
Like many other Aroids, monstera cannot tolerate overwatering.
While they do like most soil, you want to be careful not the gets the soil wet or soggy. That’s a sign that you’re adding too much water or watering the plant too often.
If this keeps happening it will lead to root rot because the roots will drown in too much water causing them to suffocate.
Once root rot sets in, part of the root system gets damaged.
As a result, the plant won’t be able to absorb nutrients or water efficiently from the soil.
Because of this, the plant’s leaves will show signs of dryness (since there are the farthest points from the roots, so only little water gets there).
The lack of moisture will cause leaf tips to burn brown. You’ll also see brown spots appear which are the plant’s symptoms of stress or distress.
That said, it is not always your watering schedule that can cause overwatering.
If you use heavy soil or soil that tends to retain moisture, it will lead to waterlogging even if you water perfected. Also, your pot needs drainage otherwise the excess liquid will just pool at the bottom and keep the soil wet.
How to Fix an Overwatered Monstera
Fixing an overwatered monstera with brown spots on its leaves means getting to the source of the problem.
First, check your watering schedule. You want to wait until the top 2-3 inches of soil is completely dry before you add more water.
If you water before this happens, there’s a chance you’ve been overwatering the plant.
Second, make sure you’re using well-draining soil.
This is essential so that any excess moisture is quickly drained out. In doing so, the roots avoid sitting in water for long periods of time.
If you’re using regular houseplant soil or anything else that holds too much water, the plant may also be at risk of overwatering.
Third, ensure that the pot the plant it in has drainage holes. If there are no holes, then the liquid will just build up at the bottom of the container with no ways to get out. This keeps the soil wet.
The other thing you need to check for when your monstera leaves have brown spots is root rot.
If the plant has been overwatered, it may or may not have root rot.
The only way to tell for sure is to unpot the plant and check the roots.
Rotted roots have a foul smell. They are black, soft and mushy. Meanwhile, healthy roots don’t have much of a smell. They are also white, pliable and somewhat firm.
If there is no root rot, repot the plant and let the soil completely dry before you add water again. Also, adjust your watering schedule. This also means the cause of the brown spots on your Monstera is one of the other reasons below.
If there is root rot, you will need to prune the rotted roots. Then proportionated prune the plant to the amount of rotted roots you pruned.
This gives the plant a better chance of survival since fewer roots can support a smaller plant.
You’ll also need to rise the roots with hydrogen peroxide if the cause of root rot was fungal. Throw away all the soil in this case. And, clean the pot with hydrogen peroxide solution as well.
Once done, let the roots dry and plant it in a new pot with new, fresh, well-draining soil.
Finally, pray that the plant recovers on its own.
You’ve done all that you can. Now, the plant has to recover on its own.
Too much light, direct sunlight and exposure to very intense light will cause the leaves to get discolored. After a while, they will get burned. Additionally, brown or black spots will develop as well on the leaves.
All these are signs that the plant is getting too much light.
The thing is, the monstera thrives in plenty of light. But it needs bright, indirect light. As such, the light needs to be filtered, dappled or diffused.
Direct light from the sun’s rays or putting grow lights too near a plant will damage the leaves and cause brown spots among other things.
That’s because the monstera comes from the tropical rainforest. There, it lives under much larger trees whose leaves and branches make up the forest canopy overhead.
This gives the plant some kind of shade from the harsh rays of the tropical sun.
Thus, the plant receives filtered or dappled light and is not used to exposure to the sun’s direct rays.
How to Fix Too Much Light
This is one of the easiest causes to fix since all you need to do is move the plant to a less bright location.
What I mean specifically is to move the plant to bright, well-lit spot with indirect light.
When choosing a place to position your monstera, avoid direct contact with the sun’s rays especially during mid-day. Also, keep it away from a dark place since that will negatively affect its growth.
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Brown spots on Monstera leaves can also signify infection. This could be bacterial or fungal. And you’ll be able to tell by examining the size and behavior of the brown spots of the leaves.
Basically, the brown spots represents the areas that are affected by disease.
If the infection is fungal,
You’ll initial only one brown spot. Other spots will then appear. If left to develop, the spots will get bigger until they touch one another, giving you one big brown blotch.
If there is still no treatment, the entire leaf will turn brown and fall off.
This will happen to many leaves as well.
If the infection is bacterial,
You’re dealing with bacterial leaf spot disease. Here, not as many leaves will be affected. But the spot will be larger than those in fungal infections.
In both cases, you will need to deal with the infections, be it bacterial or fungal. More importantly, the sooner you do, the less damage it can cause.
How to Treat Disease on Monstera
The first thing to do with leaf spot disease is to figure out whether is it fungal or bacterial. The two have different symptoms. And they have different treatments as well.
If it is a fungal infection, then you can treat the plant with fungicide spray. After resolving the problem, you can remove all the affected leaves.
On the other hand, if the cause is a bacterial infection, you want to check whether the disease is affecting the leaves only (it is localized to the foliage) or the entire plant (systemic).
If the bacterial infection is localized, you can remove the leaves and carefully throw them into the trash. Unfortunately, you cannot treat or control a systemic bacterial infection.
Thus, if the latter is the case, you’ll likely end up throwing the plant in the trash. Also make sure to throw all the soil along with it because that contains the pathogens as well.
Then clean the pot with bleach solution or hydrogen peroxide solution.
Lack of Water
While not as common as overwatering, underwatering can lead to brown spots on Monstera leaves as well. This is due to dehydration.
Since the rainforest is damp because it rains a few times a day there. As such, the plant gets enough moisture from its environment. However, the roots are able to dry quickly.
As such, when you let the soil dry out, the plant will have issues because of lack of water. This can cause browning of the leaves as well as brown spots on foliage.
How to Fix Monstera Lack of Water
Water the plant. This is another simple solution.
However, that makes it a lot simpler than it really is.
Before you add water, make sure to check the soil first. Feel the soil to see whether it is wet or dry.
If the soil feels wet or soggy, don’t water. Odds are the plant is overwatered already. However, if the soil feels very dry, it means the plant needs watering.
In the latter case, soak the root ball then allow it to drain completely afterwards.
Monstera can experience pests. While not pests magnets, these insects can come and attack the plant.
Among the most common pests problems including spider mites, scale and mealybugs. These are very tiny insects that are hard to spot unless you look thoroughly under the leaves and in the joints between the main stem and the petioles.
Also, they feed on the plant by sucking on its sap. This makes them very dangerous especially because they grow very quickly in number.
As such, collectively, the can cause a lot of damage as they take moisture and nutrients from the plant.
How to Get Rid of Pests on Monstera Plant
The first step to getting rid of pests on Monstera plants is to find them. Regular inspection is the only way.
And if you suspect there is a pest problem, look behind the leaves where they usually hide or lay their eggs.
You need to look closely since they are very tiny. Although, it becomes easier to spot them when they turn into an infestation because they look like clumps due to their number.
If you spot pests, immediately isolate the plant since these bugs can spread to other nearby houseplants. Also, check any plants in proximity to the affected monster just to make sure.
The first line of defense is spraying water. Use a showerhead or garden hose. But don’t use too strong a stream as you don’t want to damage the leaves.
Spray thoroughly and try to get any adult, eggs, or larvae. The stream of water will dislodge them and carry them away from the plant.
You can also use neem oil spray. But make sure to dilute it with enough water. Too much concentration will damage the leaves after getting rid of the pests. Too much can also eventually kill your plant.
Once a week or twice a week application over several weeks should work. Stop once there are not more pests.
The monstera does not need fertilizer. But if you feed it, it will grow faster, reach taller heights and produce more (and larger) foliage.
So, plant food is a good thing.
But too much plant foot results in fertilizer burn. And this begins with the roots. However, it will work its way up and you’ll soon see brown leaf spots, leaf tips and edges.
Thus, avoid over feeding the plant.
How to Fix Fertilizer Burn on Monstera
The best solution for fertilizer burn or an overfertilized monstera is to flush the soil.
This will allow the water to dissolve the salts and excess minerals and carry them out of the soil along with small particles and debris. In doing so, you get rid of the excess salts that cause fertilizer burn.
Because you will keep fertilizing the plant throughout its lifetime, it is a good idea to add flushing the soil to your routine. You only need to do this every few months to ensure that the salts from fertilizer don’t built up.
To flush the soil, run water through the soil using a garden hose. Don’t wet the plant just put the hose of the pot and let it soak the soak.
You can reposition every now and then to distribute the water.
Do this for 5-10 minutes and let the water keep dripping down from the holes below the pot.
The goal is the let the running water carry all the debris and tiny particles in the soil including the salts and excess minerals out.
Then, let the soil completely drain right after.