What Is That White Mold On Plant Soil & How to Get Rid of It

white mold on plant soil
White mold is a harmless saprophytic fungus present in organic gardening soil. It's prevalent in indoor plants due to the damp environment caused by overwatering, poor drainage, insufficient lighting and air circulation, and contaminated potting soil.

Why Is There White Mold On My Houseplant Soil?

Houseplant soil can sometimes become contaminated by white mold, also known as “white fuzzy mold.” The contamination may have occurred from using unsanitary soil like sand or peat pots.

It signifies that your plant’s environment isn’t clean or healthy. You should check the area and remove any equipment or materials like dead leaves causing this problem.

When you buy potting soil, it should be free of dust and other particles. The white mold on your soil is not harmful to the plant but can leave the soil feeling unpleasant to touch.

When you notice the white mold on your plant soil, it’s time to change what you use to improve the soil quality.

If a houseplant is suffering from white mold spores, it’s a symptom that one or more of its roots, possibly due to a clogged drain, are drowning. This can also be caused by overwatering and lack of drainage.

What Causes White Mold?

White molds are caused by fungi that feed on moisture on damp surfaces and utilize it to grow into powdery mildew.

Mold fungus thrives in dark, moist, and stuffy areas, which is typical for indoor houseplants.

Let’s dive deeper into the major culprits that cause mold in plants.

1. Overwatering

Overwatering your indoor plants results in soggy soil and humid air, which leads to a damp environment that is a perfect breeding ground for mold.

Potted plants with excess water are highly susceptible to root rot and accelerated mold growth resulting in moldy soils.

On the contrary, outdoor plants can survive in excess water due to the direct sunlight and open spaces that make soil dry out more quickly than indoor plants.

2. Insufficient Lighting

Different plants have specific sunlight requirements, and an inadequate amount may lead to a longer drying time.

Damp houseplant soil makes the plant’s root rot quickly. Poor lighting also leads to stunted growth, colored leaves, and unhealthy indoor plants.

3. Poor Drainage

Drainage is an important consideration when it comes to indoor gardening. A poor drainage system is caused by dense potting mix, incorrect pot size, and containers without drainage holes.

Proper pot size is essential to prevent root exposure and hold sufficient water for the plant to thrive. Otherwise, a smaller pot may cause your plant’s roots to rot.

Dense soil holds in more water trapping more moisture, creating a thriving condition for mold growth.

Replace with lighter soil or water less frequently, ensuring the plant gets enough sunlight to dry soil.

4. Poor Air Circulation

Air movement helps indoor plants dry out between watering. In cold seasons most indoor plants suffer in those dark and cramped shelves and become highly susceptible to white molds due to poor airflow.

Is Mold On Plant Soil Bad For Plants?

White mold on plant soil is not necessarily bad for plants. In fact, some species of fungi can be beneficial to plants in the soil.

As growers, you ought to ask whether these organisms affect your crop yield and if they can cause adverse effects. The answer may depend on certain conditions, such as the type of fungus and how severe the infestation is.

White mold typically appears as small, white spots on top of the soil. These spots may contain visible specks of mold spores or fine powdery mildew and can cover an entire plant.

If you find these spots growing across your plants’ leaves or if they are constantly found on a single stem, it indicates a systemic fungal problem in your plant’s root system.

This can result in your plant’s death due to a lack of nutrients, stunted growth caused by chlorosis (greening), and other symptoms of nutrient deficiencies, such as yellowed leaves and leaf wilt.

This is also dangerous for humans, who might inhale spores into their lungs when opening windows during a heavy rainstorm.

How To Get Rid Of Mold On Houseplant Soil: Quick Fixes

White mold can be a real pain to deal with. It’s not harmful to your plants, but it’s often unsightly and difficult to remove.

You can do many things to get rid of mold in your houseplants: use more organic soil, prevent the mold from forming in the first place, remove it as soon as you see it, and keep the surface of the soil clean.

Here are some fixes:

1. Use a Fungicide

The most powerful way to get rid of mold on houseplant soil is by adding a natural antifungal product to your soil.

Most plant parents sprinkle cinnamon or neem oil on the soil’s surface as a natural fungicide to eliminate mold and other pests.

You can also add some perlite, which helps keep the air flowing in and out of the soil so it will dry faster.

Spraying diluted baking soda or apple cider vinegar on the potting soil is another natural way to kill the fungus.

2. Manual Removal

Remove white molds as soon as you spot them, and to avoid mold growth, simply repot the plant in fresh soil to replace the contaminated soil. Ensure to keep the surface of the potting soil clean to prevent fungal growth.

If you cannot remove mold, it is best to cut off small portions rather than trying to remove them over large pieces because it may cause damage beyond just patching up your greenhouse or garden soiling.

3. Add an Organic Matter

You can fix this problem by adding more organic matter to your soil, like compost or manure.

This will allow the water to drain away from your plant’s root zone and remove mold from the garden soil.

How To Prevent New Mold From Growing

  • To prevent white mold from growing, ensure that your soil has enough calcium and magnesium to balance its nitrogen content. If you aren’t sure whether your soil has enough calcium or magnesium, you can test it by adding a few drops of vinegar to your potting mix. If it bubbles vigorously for about five seconds, it has enough calcium and magnesium for white mold prevention.
  • The best way to prevent new white mold from growing on your plant soil is to ensure you’re watering it correctly.
  • When you water your plants, ensure you water them in the morning or at night. This will help them absorb the water more efficiently and keep the soil from becoming too soggy. 
  • You should also check the temperature of your home before giving your plants a drink—if it’s too hot or too cold outside, they may not be able to absorb enough moisture from their surroundings to stay healthy.
  • It would be best if you also tried using potting soil with less water retention properties, like cactus mix or peat moss.
  • It may be easiest to use a small container with drainage holes in the bottom so that excess moisture can escape as it drains out of the pot.


Discovering composting as a way of life or even better, as nature’s way of recycling, Ana dedicates her time to trying out new methods of composting at home. Her goal is to share everything that she’s learned in the hopes that it will help others discover the amazing rewards of composting.

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