Why Is There Mold on My Houseplant Soil and 4 Ways to Fix It

Mold in a flowerpot with a plant - Why Is There Mold on My Houseplant Soil and 4 Ways to Fix It

Have you noticed mold on your houseplant soil? Molds typically grow on indoor plants or after you bring your plants indoors for the winter. Molds can appear on your new indoor plants or established leafy plants.

The reasons for mold on your houseplant are, contaminated soil, overwatering, poor air circulation, poor drainage, dead leaves on the surface. The four ways to fix it are: take your houseplant outdoors, physically remove the mold on the soil, treat mold with natural fungicide, repot your houseplant.

Why is there Mold On your Houseplant Soil?

Mold thrives in moist, stuffy, and dark environments. Unluckily, these conditions are easy to create on your houseplants. So, what causes mold to appear on your houseplant soil?

White fuzzy mold is not as dangerous as it appears. Mold on your houseplant soil may or may not harm your plant, depending on the type of mold you are dealing with. It can, however, affect the appearance of your houseplants.

The arrival of mold on your houseplants can be toxic, especially if there are members of your family with allergies and asthma. So, you will want to instantly get rid of it for your plant and yourself.

There are several reasons molds appear on your houseplant soil. Knowing what caused them to appear and ways to fix it will keep your plants and home happy.

Mold on Potplant - Why Is There Mold on My Houseplant Soil and 4 Ways to Fix It

Contaminated Soil

Your potting soil can be one of the causes molds develops in your houseplant soil. Soil should have some microorganisms, but it can be contaminated even before it is placed in a pot.

Expert gardeners find it is important to always inspect the bag of potting soil. A punctured bag of potting soil, even if well-stored can absorb moisture.


The fungus will always devour the remaining water in your houseplant. Too much water can cause your plants to develop root rot.

Houseplants do not need to be watered often. While wide-open spaces and direct sunlight makes outdoor plants dry out quickly, houseplants retain water longer because they are in enclosed areas and get only indirect sunlight.

Poor Air Circulation

Houseplants often do not get enough air circulation, especially when windows are closed in the winter. Houseplants that are kept on overcrowded shelves or in dark corners are particularly prone to this issue, too.

Good air circulation helps houseplants dry out between watering schedules.

Poor Drainage

Excess moisture in houseplants is caused by poor drainage. Not using the right-sized pots, dense soil, and lack of drainage holes in the pots cause poor drainage.

A houseplant grown in an oversized pot is prone to root rot because the roots cannot consume the amount of water in a large pot. So use a pot that is proportionate to your plant.

Pots, especially decorative pots, often do not have drainage holes. After passing through the soil, drainage holes allow excess water to get out of the pot.

In the absence of drainage holes, moisture is retained around the roots making them susceptible to mold and fungus.

Dense soil has trouble escaping the pot, too. It is better to use potting soil for your houseplant because it contains peat moss and perlite that is lightweight and can help drain water.

You can amend dense soil by adding plain peat moss or you repot your houseplant in the right potting mix.

Dead Leaves on the Surface

Dead leaves encourage the growth of mold on soil because mold and fungus feed on decaying plant matter. You should, therefore, remove dead leaves before they pile at the base of your houseplant.

How to Get Remove Mold on Plant Soil

Mold can be harmless or deadly to your houseplant and should be dealt with.

It is important that you should first identify the type of mold on the soil of your houseplant so you can properly deal with it.

White Mold

White mold appears feathery, cottony, and hazy on the surface of the soil of your houseplant.

White mold is a saprophytic fungus that feeds on dead organic material. It is not harmful to your houseplants and humans, even if there is lots of it.

White mold settles on the soil surface that is damp and with limited ventilation.

Powdery Mildew

Powdery mildew appears on the stems and leaves of your houseplant as a white powdery film looking like a dusting of flour. It may have a darker appearance (grey color) over time and spreads to the soil.

Powdery mildew stunts the growth of your houseplant and can kill your houseplant when left untreated. It can also impair photosynthesis.

Grey Mold

Grey mold presents itself as dusty grey spores found near the surface of the soil. They can also appear in the dense areas of the foliage of your plant.

The airborne spores of the Botrytis (a fungus) settle on dying or diseased tissue as well as on open wounds of your plant.

Grey mold causes the affected areas of your plant to quickly enlarge and cause the collapse of the tissue. Grey mold can kill your entire houseplant if left untreated.

Sooty Mold

Sooty mold appears as dark green or black sooty-looking patches. It typically appears on the surface of the soil and the base of the plant.

The appearance of sooty mold in your houseplant means it is infected with tiny insects that feed on your houseplant’s sap. Sooty mold does not directly harm your houseplant, but when untreated, will reproduce and inhibit photosynthesis.

Yellow Fungal Mold

The yellow mold that can grow on your houseplant soil is also a type of saprophytic fungi that is harmless.

4 Ways to Remove Mold from Your Houseplant 

Getting rid of mold on the soil of your houseplant is an easy task if you know what to do.

It is common for people to think that molds on the soil mean the end of your houseplant. It is not!

If your houseplant already has mold on the soil, preventive care is no longer an option. It is a must that you remove the mold on the soil so you can create a new environment where mold will not thrive and grow.

Here are 4 ways by which you can get rid of mold on your houseplant soil.

1.     Take your Houseplant Outdoors

Take your houseplant outdoor to allow the potting soil to dry in direct sunlight and eliminate mold.

Damp soil is a haven for mold; thus, you should never allow your plant to remain consistently wet.

Allow the soil of your houseplant to dry. Take it outdoor and expose it to direct sunlight and enough air circulation.  The dry condition and the heat from the sun will kill mold on your houseplant soil without drying or burning your plant.

Taking your plant to dry out in the sun works well in killing mold because it hates the sun.

Molds live in the top layer of the soil and the heat of the sun will quickly dry out the soil.

You can use a sterile spoon to scoop out the remaining white feathery residue.

Choose to dry out your plant by placing it in a spot pot outside where it can get direct sunlight.

Taking your houseplant outside to kill mold will work fine when the presence of mold is not too severe.

2.     Physically Remove the Mold on the Soil

Physically removing the mold from the soil is one of the easiest ways to get rid of it.  Mold typically affects only the top part of your potting mix, so you can use a sterile spoon to scrape the top 2 inches of the soil.

Make sure that none of the infected soil falls back into your pot as it can contaminate the rest of the soil.

After removing mold from the soil, remove any mold on the leaves and stems of your plant with a damp cloth. Thoroughly cleaning your plant will ensure you have removed all spores and traces of the mold.

3.     Treat Mold with Natural Fungicide

 There are several fungicides to choose from, but natural fungicide solutions will keep your home safe from chemicals.

Here are some natural fungicides you can use to remove mold on the soil of your houseplant.

Neem Oil

Neem oil is a natural fungicide found in the seeds coming from the neem tree. You can make a neem oil solution by mixing two teaspoons of neem oil and one teaspoon of dish soap for every half gallon of water.

You can use this solution to thoroughly water your contaminated houseplant. Water again with the neem oil solution only when the soil dries out.

You can flush your houseplant with neem oil once a month to prevent mold and fungus from growing again.


You can sprinkle cinnamon powder on your houseplant to kill the fungus. You can also opt to sprinkle cinnamon on the top layer of the soil to directly deal with the fungus.

Apple Cider Vinegar

You can mix 3 tablespoons of apple cider vinegar and one gallon of water. Spray the mixture on your houseplant and it will kill mold growing on the soil.

Baking Soda

Mix 4 teaspoons of baking soda and one gallon of water. You can also use potassium bicarbonate in place of baking soda for a more effective solution. Spray the solution on your houseplant and it will kill fungus in the soil.

4.     Repot your Houseplant

If you do not have the patience to remove mold on your houseplant with the methods mentioned above, you can repot your plant and completely get rid of mold in one go.

Repotting your houseplant and planting it in new and fresh potting soil is the best way to kill mold in your houseplant soil. Repotting will give your houseplant a fresh start and will prevent mold from returning.

When repotting, make sure you do not transfer any mold to the new pot. Always make sure to use sterilized tools – knives, pruning shears, and other implements.

This is how to repot your houseplant to remove mold on the soil:

  • Use a damp cloth to get rid of any signs of mold from the stems and leaves of your houseplant. Rinse off the roots, too.
  • Spray your plant with a mild fungicide to ensure no mold spores remain.
  • Remove your plant from its pot.
  • Empty the soil from the pot.
  • Prune any part of the plant that shows any sign of disease.
  • Fill your new sterile pot with sterile potting soil (one-third full).
  • Place the plant in the pot and fill the pot with soil.
  • Water your plant.

Make sure to water your houseplant regularly when the top layer of the soil dries out.

You can sterilize your old pot or use a new one. You can give the pot a few sprays of natural fungicide or soak the pot in a mixture of 1 part liquid bleach and 9 parts water for a few minutes. Rinse the pot with water and dishwashing liquid and allow it to dry.

Make sure, too, that you use fresh sterile soil.

Repotting is the only method you can use for severe mold issues.

What is the Mold in your Houseplant Soil? 

Mold is a fungus that consists of tiny particles that continuously float around the air.

Mold in the air that is present under normal conditions and at low levels is typically not a health concern. However, mold in your houseplant soil can make it prone to root rot and damage your plant.

Higher levels of mold in your home can also decrease air quality and can affect humans and pets even if you have an air purifier.

The unpleasant sight of mold on your houseplant soil and around the base of its stem will not harm your plant. The appearance of gray or white fungus, though, tells you that there are some plant care issues.

It is important that you identify the type of mold present to determine if it is dangerous.

You can identify common types of molds based on their color. Some molds, although of  the same color can be of different types.

Final Thoughts – Why Is There Mold On My Houseplants? 

Mold growth is not the end of your plant! There are several remedies you can use to fix the situation. While drying your plant in the sun, physically removing mold, and applying natural fungicide will get kill mold off your houseplant, repotting is the best method to kill mold on the soil.

A good combination of soil, sun, air, and water will allow your houseplant soil to keep its natural balance. These, too, will prevent the growth of mold on your houseplant soil.

Jenny Marie

Tribal Writer

Edited by

Patricia Godwin

Patricia Godwin

Patricia has many years of experience as a content writer on various subjects, but her first love is gardening. She’s never met a plant she didn’t like and, consequently, she writes about every type of plant you can think of. Once an avid gardener with a herb garden, a succulent rockery, and a rose garden – to mention a few. Nowadays, she’s constantly on the move searching for interesting plants to bring to your attention; and explain to you all the details you need to grow, care and maintain these plants.

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