Close up of leaf spot disease of Monstera Borsigiana plantBacterial leaf spot often proves to be quite a fatal disease for plants, which is why you must catch it early on so it can be treated promptly. If you think your Monstera is suffering from this infection, you don’t have to worry.

Read our complete expert guide to find the causes, symptoms and treatment options for this infection.

What Causes Bacterial Leaf Spot on Monstera?

The leaf spot disease due to bacteria is a serious infection that can be caused by a number of bacterial species such as Pseudomonas, Xanthomonas, Erwinia, etc. Overwatering and warm, moist environments are the main predisposing factors for its development. This infection usually affect your household monsteras like Monstera deliciosa.

You can read all about what causes this disease here.

– Transferred From Another Plant

This disease spreads very rapidly from one plant to another. Plants that are kept close to each other will succumb very quickly one after another with brown spots and black spots erupting all over them. This is because tiny bacterial spots are easily transferred across small distances by air currents and insects, etc.

– Overwatering

Overwatering is one of the primary causes of this disease in the monstera plant. It causes your soil to be runny and wet all the time. The soil is already a place with poor sunlight and air circulation, so of course, it serves as a breeding ground for bacteria that can then cause leaf spots to develop on the affected plant. This also leads to the development of root rot in the plant.

If you water your plant without waiting for the top 3 inches of the soil to become dry, then this comprises overwatering. Also, check the drainage of the pot as well as the soil. If any of them is storing water, then it’s time for a change.

– Moist and Humid Conditions

This plant needs high humidity as part of its basic care needs, but combined with overwatering and poor air circulation, this could spell major trouble. It produces the exact conditions that bacteria love to thrive under.

– Use of Infected Gardening Tools

Your gardening tools might be the biggest culprit when it comes to causing this infection. Not many of us remember to clean, wash and then properly disinfect our tools after using them. That is why they are always found to carry bacterial spores from an infected plant to a healthy one. 

You must also keep in mind that merely washing your tools isn’t enough. They should also be disinfected afterward using a strong disinfecting solution. Rubbing alcohol also works pretty fine in our experience.



You can treat those tiny brown spots on Monstera leaves by using either DIY measures like baking soda or neem oil. You can also go for more commercial options like bactericidal agents and bactericides.

Want to find out about all these treatment options in detail? Then carry on reading below.

– Isolate and Quarantine

The most important thing to do when you notice the first signs of spots or leaves turning yellow is to isolate your plant. Move it as far away from the rest of your plants as possible.

Bacterial infections are highly contagious. They will spread from one plant to another rapidly. Also, take care that any tool used on the infected plant is properly disinfected before use on another plant.

– Prune the Most Severely Affected Parts

Now, some of your plant leaves might be so severely affected that they cannot be salvaged at all. Prune them off using sharp gardening shears or scissors. Also, remove any severely rotten piece of stem that looks too damaged to be saved. 

Occasionally, the majority of your plant might be rotten. It will be best to simply say goodbye to it at this point. Make sure to dispose of it by burning it as this plant cannot even be recycled.

An infected plant should never be added to compost or used as mulch. It will spread the infection to the entire pile of compost and destroy all plants to which that compost is then added.

– Use Baking Soda

Baking soda is the most useful kitchen item for solving common problems of plants. It can be used as a foliar spray on the infected plant. Not only is it effective against bacterial infections, but it is also used to treat fungal leaf spot Monstera. Whenever you see your leaves turn yellow and spotted, you need to bring your baking soda out.

– How To Make Baking Soda Foliar Spray

Foliar spray is easy to make and very convenient to apply. Here are the two easiest recipes for it.

Take one-quarter of a gallon of water and add one teaspoon of soda to it. Also, add a few drops of dishwashing soap to the mix. Your DIY baking soda solution is now ready for use.

There is another method to make a sodium bicarbonate foliar spray. In this method, you add four teaspoons of baking soda to one whole gallon of water. Throw an ounce of common vegetable oil in it. This mixture is also pretty effective when it comes to getting rid of this problem.

– How Often To Use Baking Soda Foliar Spray

You should spray the baking soda mixture on the plant every week or every second week. Spray lightly all over the plant. Make sure not to miss any spots under the leaves. 

Baking soda can be quite harsh on plants, and its uncontrolled use will cause chemical burns to your plant. That is why you must be careful not to use too much of it. Also, don’t use this mixture too frequently. 

– Use Neem Oil

Neem oil is one super ingredient to have in your pantry. It is a natural antibacterial and antifungal agent. You can use it to treat bacterial black and brown spots as well as leaves drooping in your Monstera plants. The best thing about using neem oil is that it is completely safe and poses no harm to your plant whatsoever.

There are two ways you can use neem oil to treat bacterial spots. One is by directly applying the oil, and the second method is by making a spray.

Learn about both these methods by carrying on reading below.

– Buy Good Quality Oil

Make sure to buy only the most authentic neem oil that you can find. The purer it is, the more effective it will be. 

Commercially packaged store-bought ones are also not bad. You can totally go for them as a second option. Make sure they are from an authentic and well-reviewed source.

– Apply Oil Drops Directly to the Plant

Take a Q-tip and moisten it with a couple of drops of neem oil, then apply it to each infected Monstera leaf one by one. Especially apply it to the brown and black spots individually.

Do this entire procedure once each week. A major downside to this method is the huge amount of time and energy that it takes.

– Use Neem Oil Foliar Spray 

A foliar spray is more convenient because it saves a lot of time. All you have to do is to make it one time and then keep spraying it at your disposal.

  • An alternative approach to using neem oil is to make a foliar spray. Add one teaspoon of neem oil to one liter of water. Also, add one teaspoon of liquid dishwashing soap to it.
  • Fill this mixture with a spray bottle. Use it to spray lightly on the infected plant once each week. You can keep spraying until symptoms begin to recede.
  • Even after your plant has revived, continue this spraying at least two to three times a month. This is to make sure that the disease doesn’t come back.

– Purchase Copper and Pyrethrins

Copper and Pyrethrins are two unique and innovative ingredients. They are used nowadays to treat a variety of plant problems such as Monstera diseases like bacterial rot and pests like spider mites

These two ingredients come in the form of packaged dust. You can buy this dust and cover the top and underside of the yellow leaves uniformly with it. Keep reapplying every week until the symptoms disappear completely.

– Use Bactericidal Agents

Sometimes, commercial bactericides might be your only option. Take care to buy only the most high-quality ones and always follow the instructions given on the back of the label.

There are two main types of bactericides you can use for Monstera leaf spot treatment. Find out what they are in the upcoming section.

– Liquid Copper Bactericide

This product is very potent, so care needs to be taken when using it on the plants. 

There is no better substance to kill bacteria than liquid copper. It will get rid of the yellow and brown spots on monstera leaves very quickly, but it is also detrimental to other plants and humans. 

That is why you should strictly follow the instructions given on the label. Wear protective clothing and eyewear to protect yourself when using this fungicide.

– Sulfur Plant Bactericide

Sulfur bactericides are safer and, according to some, a better alternative to using liquid copper.

Sulfur-containing bactericides are effective not only against bacteria but also against fungal spores. You can also use them to treat any kind of Monstera fungal infection. They are also relatively safer for use by humans.

– Improve Cultural Care

Remember that no bacterial leaf spot treatment will be effective unless you improve the conditions in which your plant is growing. Learn some basic care needs of the Monstera plant below.

  • Monstera species are best grown as indoor plants under indirect light. This is because its leaves cannot tolerate direct sunlight.
  • Keep this plant at a temperature above 60 degrees Fahrenheit.
  • Increase humidity around them by more than 50 percent, or you will find your Monstera leaves turning light brown and curling around the edges.
  • Keep away from overwatering the plant. Also, make sure that air circulation and drainage are not compromised.


Does Bacterial Leaf Spot stay in the soil?

No, Bacterial Leaf Spot doesn’t stay in the soil. It spreads through water, tools, and plant debris. Proper sanitation can prevent its spread.

Are pesticides effective against Bacterial Leaf Spot Monstera?

No, pesticides are not effective against Bacterial Leaf Spot caused by bacteria. Prevention measures and removing infected leaves are recommended.

Will repotting cure Bacterial Leaf Spot Monstera?

No, repotting alone cannot cure Bacterial Leaf Spot. Removing infected leaves and improving growing conditions can help control the disease.


Read a brief conclusive summary of this article here.

  • Monstera species are prone to getting bacterial infections from a variety of bacteria. This mostly happens when the plant is subjected to prolonged moist, humid, and wet conditions.
  • These diseases produce spots on the leaves. The leaves might also start curling or falling. Eventually, the plant will begin to die.
  • Isolate the diseased plant first, then use neem oil or baking soda to get rid of the infection naturally. 
  • You can also use bactericidal agents to treat your plants. Don’t forget to improve your plant’s watering needs and air circulation too.

The most effective way to get rid of the bacterial spots is to prevent them. Take note that your plant needs plenty of sunshine, warmth and air circulation.

5/5 - (18 votes)
Evergreen Seeds