The Monstera genus is a group of exotic and delicate plants popularly grown as indoor houseplants. While native to the harsh environment of the tropical regions of Central and South America, these plants are susceptible to all kinds of problems.
One of the common problems that Monstera faces is brown spots. Read here to find out why your Monstera has brown spots and what you can do to fix it.
Why does My Monstera Have Brown Spots?
You can tell how healthy Monstera is by its appearance. However, brown spots are not an indication of healthy growth. There are many reasons why your Monstera has many reasons, and you must go through all of them to find out the problem.
To make it easier, we have compiled a list of possible reasons why your Monstera has brown spots.
1. Watering
One of the most common reasons for brown spots on Monstera is watering issues. Monstera generally does well if you water them once every two weeks and grow them in a pot with drainage holes. However, improper watering can lead to the browning of the leaves.
Underwatering the Monstera plants results in a water deficiency, causing the Monstera to wilt, leading to brown edges of the leaf. Since the Monstera is not receiving enough water to grow, the leaves start to turn brown and crispy.
However, overwatering the Monstera leads to a similar issue. Overwatering Monstera occurs when you water the Monstera too frequently or the pot isn’t draining well. Overwatering causes the roots to suffocate as they decrease the passage of oxygen, causing them to rot.
Root rot causes dark brown or black spots on the leaves and browning of the stem. This is because the roots can no longer absorb the required nutrients to stay healthy.
Additionally, the type of water you give Monstera is another factor that can result in brown leaves. Since tap water contains chlorine and other chemicals that treat water, they can cause brown spots on Monstera leaves.
2. Bright Direct Sun
As tropical plants, Monstera is accustomed to bright, filtered light that passes through the forest canopy. Hence, they generally do well in bright indirect sunlight. However, while Monstera plants can survive some direct sunlight, excess light can lead to scorching.
Too much exposure to direct sunlight causes the Monstera leaves to burn and turn brown. Monstera plants do not tolerate harsh sun and will let you know they need shade if the Monstera has brown leaves.
The ultraviolet rays in the sun can damage leaf cells. Hence, not only do you need to be wary of the intensity of the light, but the amount of exposure as well.
3. Humidity
In their native habitat, Monstera plants are accustomed to high humidity levels. Humidity controls the rate of transpiration and absorption of water and nutrients by the aerial roots.
Hence, lower humidity levels can result in Monstera leaves developing brown spots.
However, suppose the humidity levels are too high. In that case, it is an open invitation to parasitic and pathogenic organisms that thrive in humid environments and can cause infection in the Monstera leaf, creating brown spots.
4. Temperature
Monstera plants are susceptible to temperature changes. While they do not tolerate frost, they do not like hot climates. If the environment is too hot, it can cause heat stress in the plant.
The plant’s defense responses kick in, and it starts to wilt, leading to lower rates of photosynthesis and water intake, eventually resulting in crisp and brown Monstera leaves.
On the other side of the spectrum, if the environment is too cold, “chill spots” develop on the leaves. These regions are where the water in the Monstera starts to turn into ice crystals. These crystals then damage leaf cells, and the spots start browning.
5. Diseases
One of the leading problems that Monstera owners face is plant diseases. It might be infected if your Monstera plant has small brown spots all over the Monstera leaves.
Monstera’s most common disease is root rot, caused by a fungal infection in Monstera roots. Root rot causes browning of the leaves and brown spots on the stem. However, there are other fungal infections that can cause the plant to show brown spotting.
Another fungal infection is Rust, which causes the leaves to turn a rusty color. Rust creates lesions on the Monstera leaves, forming large brown spots.
Similarly, if your Monstera has a bacterial infection, Monstera leaves show dark brown patches with yellowing at the border. According to Clemson University, these spots usually show a couple of weeks after the infection of the bacterial leaf spot diseases.
These diseases mainly result due to a moist environment such as wet soil. However, the biggest problem with these diseases is that they are highly transmissible; they can quickly spread from one plant to another.
Fungal and bacterial spores travel in the air, so there is a high chance that if one of your plants is infected, its neighbor plant will be too.
6. Pests
Plant owners are familiar with pests that eat away their Monstera until the plant dies. Monstera common pest infestation include mealy bugs and spider mites.
These pests feed on the Monstera and cause the leaf discoloration and brown spots all over the plant, including the stem and leaf.
7. Nutrition
Monstera plants are exact in their nutrition requirements. Adding too much or too little nutrition can cause brown spots and harm the Monstera.
Adding excessive fertilizer to the pot can result in fertilizer burn. This is also true when you add fertilizer in the winter when the Monstera growth is slow.
This is because fertilizer, mainly organic, can cause osmotic stress as the water-salt balance is lost. This causes the roots to stop taking in water.
Conversely, adding too little fertilizer can result in nutrient deficiency. Most commonly, Monstera needs nitrates, magnesium, and phosphates to grow well. Deficiency in these nutrients causes the yellowing of leaves and brown spots.
8. Repotting
Monstera plant, such as the Monstera deliciosa, tends to grow quickly and too much. While a mature Monstera will have slower growth than a juvenile Monstera plant, repotting them is crucial.
If the Monstera grows out of its pot, it can cause poor drainage and stunted growth, leading to yellowing leaves, thin stems, and brown edges and spots. It can also lead to excess water that creates soggy soil, resulting in fungal diseases.
Similarly, repotting the Monstera in a pot that is too big can cause water to accumulate away from the roots.
Similarly, the Monstera requires time to adjust to the new environment and initiates stress responses, and you might see a brown spot here and there on the Monstera.
9. Aging
Finally, if your Monstera plant shows brown spots, it can be due to aging. Like all living things, the Monstera plant has a life span. As the Monstera ages, chlorophyll production decreases, and leaves start showing brown spots until they turn completely brown and fall off.
How to Fix Brown Spots on Monstera
If your Monstera has brown spots, it can be worrying. However, if you are quick to act, you can fix brown spots for any given reason.
Once you have identified the reason, read below to find out what you can do to fix it.
1. For Watering Problems
The best way to prevent or fix brown spots caused by watering issues is to act quickly. If you know how to water your Monstera properly, the brown spot problem will disappear quickly.
First, you should check the drainage of the Monstera pot to ensure that water does not accumulate. The pot should have adequate drainage holes. You should use well-aerated soil such as loam to allow better drainage.
You can use a water meter to check whether you should water the Monstera more. Alternatively, you can use the tip of your fingers to check the soil’s surface to see if it’s dry. Generally, Monstera requires more water in summer than in winter.
2. Sunlight
Avoid putting your Monstera in direct sunlight. Since Monstera does well in indirect light, place it in a room that receives plenty of filtered light. You could also place it near a south-facing window. If you place it in the garden, cover it with shade.
3. Temperature and Humidity
Monstera plants do well at a temperature of between 60 to 80 degrees Fahrenheit and humidity levels above 40%.
You can place the Monstera plant near the kitchen or the bathroom where the temperature and humidity are high.
You can also use a room thermometer to measure the temperature and a humidifier to maintain humidity levels. Alternatively, place a pebble tray below the Monstera to keep it moist.
4. Diseases and Pests
While you can prevent diseases by controlling watering and humidity levels, there is no guarantee that your Monstera won’t get infected.
A clear indication of root rot is an odor of sulfur from the soil. If the infection has spread to the stem or leaves, there is little you can do. However, you can treat the infection in the early stages.
First, isolate the infected plant and remove it from the plant. Cut off any affected leaves and roots. Then, treat it with antifungal or antibacterial soap.
For pest infestations, you can use neem oil as a repellent. You can treat pest infestations by spraying pesticides on the plant.
Spider mites are small, but you can locate signs such as webs or by checking the stem.
When repotting the plant, do not see the same contaminated soil.
5. Fertilizers
Only feed the Monstera plant during the growing seasons of summer and spring. This is because they intake more nutrients when they are actively growing. Additionally, slow-release fertilizers work best compared to fast-release fertilizers as they allow ample time for the plant to absorb nutrients without causing osmotic stress.
If you think you’ve added too much fertilizer, you can repot the Monstera with new soil.
6. Repotting
As young plants, Monstera grows quickly and must be repotted once every few weeks. Monstera growth slows down after they reach maturity and only need to be repotted once every two or three years.
A clear sign of brown spots due to repotting is when you see roots growing out of the drainage holes or the soil surface. Repot the Monstera in a larger clay pot and increase humidity and temperature levels to help it adapt to the new surrounding.
7. Aging
While there is little you can do for the natural aging process, new leaves are safe from the problem. Aging causes brown spots on older leaves, and you’ll be fine if you prune them. You can also let them be, and they will fall off independently.
Types of Brown Spots on Monstera
Your Monstera plant can get brown spots for many reasons, as seen above. In all cases, different types of spots are made. Knowing the types of brown spots can help you identify the underlying cause.
1. Large Spots
Monstera plants such as the Monstera deliciosa are known for their large leaves. These leaves can be covered by large brown spots, which usually occur because of leaf burn due to harsh sunlight.
2. Small Spots
Small spots are more common in Monstera plants and are lighter in color. These spots resemble tiny holes and are often caused by pathogenic infections.
3. Dark Brown Spots
Rarely, your Monstera plant may be riddled with very dark brown spots that almost appear black. These spots usually occur due to water issues such as overwatering or dehydration.
Identifying Monstera Spots
Before you treat brown spots on Monstera, you should identify the spots so you can quickly act on the reason. The appearance of the spots at first look gives you plenty of information on what you should do to fix it. The things to look for include the following:
· The color of the spots. Does the Monstera have tan or brown leaf spots? Does it have a yellow border?
· The shape of the spots. Are they round or irregular?
· The size of the spots. Are they large or small?
· The location of the spots. Are the spots only on the leaves or the stem? Are they only on the older leaves?
· The number of spots. Are the spots more on the upper surface of the leaf or the lower surface?
Common Questions
1. Why does my Monstera Deliciosa have brown spots?
There are many reasons why swiss cheese plant Monstera deliciosa leaves get brown spots. They could be because of watering problems such as under or overwatering and water quality, disease or pests, leaf burning, overfeeding, and more.
2. Should I cut off the Monstera leaves that have brown spots?
We recommend that you cut off any affected leaves with brown spots. Dying leaves not only look unappealing bt is an added burden on the Monstera plant as they do not photosynthesize, but the plant uses resources to keep it alive.
3. How do I treat brown spots on Monstera?
The first step to treating brown spots is to find out the underlying cause. Since there are so many reasons, it would be better to assess the situation so you can promptly and effectively fix the problem. Identify the types of brown spots on Monstera and go through the possible reasons.
4. How do I get rid of Monstera diseases?
Monstera can be treated if the disease or infection is in its early stages. Cut off any diseased part of the plant and treat it with antimicrobial soap.
You should also change the contaminated soil to avoid reinfecting the Monstera and isolate the plant to prevent the spread of the disease.
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.
