Bacterial Leaf Spot On Monstera

Native to Central America, Monstera thrives in a tropical or sub-tropical environment. While they are relatively easy growers, Monsteras do have their issues. A common one is bacterial leaf spot. Let’s look at how bacterial leaf spot presents itself on a Monstera and how you would fix this problem.

Monstera bacterial leaf spot presents in several ways: black-edged lesions, light or dark areas, and brown spots with yellow halos. The spots measure 0.197 – 0.5 inches wide, occurring on the bottom or top of the leaf. Treatment includes removing infected foliage and fungal or homemade sprays.

It’s always upsetting when your plants have any issues, and a bacterial leaf spot infection on your Monstera is no exception. Luckily if you catch this problem quickly, you can fix it as bacterial leaf spots are generally not fatal for a house plant. Still, it’s always reassuring if you know what the problem you are dealing with is and how you can fix it.

What Does Bacterial Leaf Spot Look Like On A Monstera?

Bacterial leaf spot typically presents itself on the leaves of your Monstera and can be found both on the bottom and the top of the leaf. The bacteria generally show light or dark areas on the foliage, blacked-edged lesions, or brown spots with yellow halos.

Typically these spots are similar and measure between 0.197 and 0.5 inches in diameter. In some cases, they might ooze a sticky substance, and in wet conditions, they can enlarge and run together. In drier conditions, you will find that the spots still enlarge, but rather than running, they dry out and turn a reddish-brown color, giving off a speckled appearance.

You might also find symptoms of bacterial leaf spots showing on the edges of your Monstera leaves and typically presenting itself as brownish-yellow with the tissue drying and breaking off. In this scenario, the leaves become relatively papery and delicate.

You will typically find that bacterial leaf spot will show up on the older leaves of your Monstera first before quickly moving onto the newer leaves.

Yellow monstera leaf with

What Causes Bacterial Leaf Spot On Your Monstera?

Tiny organisms, called bacteria, cause bacterial leaf spots, and they are so small you can’t see them with your naked eye. Bacteria are single-celled organisms, and the most common to infect Monstera plants are Pseudomonas cichorii.

Bacteria can reproduce themselves by diving in half, at an astonishing rate, as often as once every 20 minutes, or in some cases, it can take several hours for them to divide. Records show that bacteria reproduce quickly at 77 – 86 degrees F temperatures.

They can spread by water splashed onto leaves or by overwintering dead organic matter. In some cases, seeds come already infected with bacteria.

How Do You Prevent Bacterial Leaf Spot On Your Monstera?

Bacterial leaf spot typically presents itself in the following conditions:

  • Over-crowded plants
  • Lack of airflow
  • Wet/ moist conditions
  • Lack of sunlight
  • Organic waste piles

Overall, if your Monstera is not happy or healthy, it is more susceptible to bacterial infections.

Over-Crowded Monstera Plants

Avoid placing Monstera plants too close together with other plants and ensure that each of your plants has enough room to grow without coming into close contact with the plants around it. Overly congested plants are a breeding ground for bacteria.

If you have found that your plants have become overcrowded, you can separate the plant into two or three depending on how crowded your plant is.

To separate a Monstera, take the plant out of its container, use a sharp blade to cut your Monsteras root ball into two or more plants. The best way to do this is to look for natural divisions or sections in your plant, ensuring that each new plant has enough roots and stems.

Then you can re-pot each of your new Monstera plants into a new soil mix, making sure your mixture is aerated enough and contains the proper nutrients for optimal growth.

Related: Baby Monstera – Detailed Care Guide

Lack Of Airflow In Your Monstera

A lack of airflow through your plant can create a stuffy atmosphere inside your plant, promoting bacterial infections. If you find that your Monstera has too many stems, causing there not to be enough airflow through the plant, you have one of two options to fix this problem.

Firstly, if you think your plants have enough extra stems and a big enough root ball, you can separate your Monstera into two or more plants.

Secondly, if you have too few stems but plenty of leaves, you can remove some of the inner leaves to create better airflow through your plant.

Bacterial Leaf Spot On Monstera the plant

Wet/ Moist Conditions In Your Monstera

Wet or moist conditions create the perfect environment for bacterial infections. If you are worried that your Monstera plant remains too damp or humid, there are many ways to combat this problem.

Make sure that you are not over-misting your plant. Regular misting can leave your Monsteras’ leaves constantly wet or dampened by the mist. If you are worried about too low humidity, think about purchasing a small humidifier to create the correct moisture for your plant.

If your soil is constantly moist, you can hold off on your watering until the first 2 – 3 inches of soil is dry before watering your plant again. Bear in mind that Monstera only likes to be watered once or twice in a two-week interval.

Lack Of Sunlight With Your Monstera

Lack of sunlight and the resultant cooler temperatures can aid in bacterial infections. If you find that your Monstera is looking unhappy and you notice that it is showing signs of not getting enough sunlight, such as:

  • Growing leggy stems
  • Soil that doesn’t dry out between waterings
  • Leaves that don’t make fenestrations (the holes in your Monstera leaves)
  • Stunted or slow growth
  • Monsteras that fall or lean to one side

In this situation, it would be best to move your Monstera to an area that will receive brighter indirect sunlight. If you do not have a place that will receive better light, you might need to invest in a grow light for your Monstera.

Yellow monstera leaf with

Dead Organic Waste Around Your Monstera

The best practice is to make sure that you clean up all the dead leaves that fall into your Monstera plants container or fall around it on the ground. Dead organic matter is a breeding ground for bacteria, and removing this will help prevent bacterial infections.

How To Treat Bacterial Leaf Spot On Your Monstera

If you have found that your Monstera is suffering from a bacterial leaf spot, there are several steps you need to take to prevent the spread and fix the problem, and these include:

  • Removing the infected leaves, you should do this over an extended period as you do not wish to shock your plant by taking off too many leaves at once
  • Try your best not to over-handle your plant during the pruning process
  • Disinfect your scissors between each cut to prevent spreading the bacteria
  • Don’t water your plant from above, as this can spread the bacteria to other areas of your plant
  • Avoid placing your plant in  areas with low temperatures
  • You can spray the infected areas with copper soap or diluted neem oil
  • You can also purchase a chemical spray, making sure to follow the instructions on the packaging carefully
  • It would be best if you make sure you only spray treatments onto your plant after you have removed the infected leaves

Read more: Albino Monsteras – All About The Rare and Expensive Variegated Monstera


Bacterial leaf spot can present on your Monstera in several ways and is quite easily treatable if you manage to detect the problem early. As with most things, prevention is better than cure, so the best option would be to make sure that you avoid situations that would put your Monstera at risk for a bacterial leaf spot infection.

Best practice would be to make sure that your Monstera is getting enough sunlight, has enough airflow, isn’t too compacted, is not staying too moist or wet, and doesn’t have a buildup of dead organic waste in its container.