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Mold in the flower pot: helpful tips on what to do about mold on the potting soil.

Potted plants are a staple in many homes. And despite best efforts to keep them healthy, most houseplants struggle with growth and maintenance issues from time to time, with one of the most common problems being moldy soil and excessive mold growth. Mold growth on houseplant soil can occur in a variety of situations and after certain events in the routine care and maintenance of your houseplants. Mold in flower pots can occur in a variety of ways and can be caused by a number of triggers. However, the most common type of mold you will encounter in your planters is white mold.

White mold in the flower pot: what is it?

White mold in the flower pot - what is it?

Most people don’t know that plants have a natural balance of bacteria and other microorganisms. Just as we humans have helpful bacteria that live on our skin and in our intestines, plants also have a relationship with good bacteria and organisms that live in the organic material of plant soil. For outdoor plants, natural processes keep these microorganisms in check so they don’t become too numerous under healthy conditions. However, in indoor potted plants, these bad bacteria can accumulate in toxic amounts and kill the good bacteria. Many of these microorganisms are necessary for plant health, but they must be present in the right amounts and in the right balance. This symbiotic relationship is why a living soil is so conducive to healthy and beautiful plants. It simply means that the top layer of soil is rich in organic matter and is enhanced by the addition of composted plant material, fertilizer and soil amendments.

If you notice mold growing on your potting soil, it is often the first sign that there is a problem with the top layer of soil and the environment your plants are in.

How does mold get on the soil in your flower pot in the first place?

How does moldy soil in the pot in the first place?

As with most things in nature, there is no one-size-fits-all solution or cause for everything. If you are dealing with white or yellow mold on the soil of your potted plants, there may be a single contributing factor, or several:

  • Excessive watering and poor drainage: moist potting soil and poor drainage lead to moldy soil and mold growth.
  • Poor air circulation: molds in the home thrive best in moist and warm places, and the same is true for molds in plants. White mold spores love stagnant, moist air that doesn’t circulate much.
  • Contaminated soil: Starting with contaminated or infected soil will only spread the mold further.
  • Decomposing leaves: if your potted plant is shedding dead leaves, they should be removed as soon as possible.

Mold in the flower pot – what you can do.

Mold in the flower pot - what you can do

If you want to know how to remove white mold on plant soil, the following steps can help you sterilize your soil, clean your plants and effectively remove moldy soil.

Repotting to get rid of mold on houseplant soil

If you conclude that the outbreak warrants repotting the plant, you should use fresh soil and a new pot. If you plan to reuse your existing plastic or ceramic container, clean it thoroughly with water and bleach. Dry the pot completely before filling it with soil. Before repotting the plant in the freshly cleaned pot, rinse the roots of the plant and wipe any mold residue from the leaves. If spores remain, you could end up with re-contamination.

If you have a terra cotta pot, replace it with a new one. Dry the pot completely before filling it with soil.

Moldy soil in the flower pot – home remedies help.

Mold in the flower pot - helpful tips on what you can do about mold on the potting soil.


If you add a natural antifungal to the soil, you can improve the situation. Some good natural remedies are cinnamon, vinegar and baking soda:

  • Cinnamon

Sprinkle a light layer of cinnamon on the surface of the potting soil. Cinnamaldehyde, a chemical compound in cinnamon, is a natural antifungal agent. Using cinnamon is a great, all-natural way to control the problem without the use of chemicals.

  • Baking Soda

Mix 2 teaspoons of baking soda with 1 quart of water to make a spray that will kill the fungus. The high pH of baking soda will kill the white mold.

Expose the plant to sunlight

Ultraviolet rays from direct sunlight destroy mold, so natural sunlight is an effective way to kill spores. Simply place the houseplants in a sunny spot outdoors. The sunlight will seamlessly do its job. This method is especially useful if the mold is growing on the surface of the soil. Even go a step further and spray the soil spread out in the sun with a solution of baking soda and water. The baking soda will absorb the moisture from the spores and help prevent the outbreak of mold growth in the future.

Mold in the flower pot: removing the top layer of potting soil.

Removing the top layer of moldy soil

First, take proper precautions for your health by wearing a mask during the process. Take a spoon and remove the top 5 inches of soil. After that, take a damp cloth and wipe off all the mold residue on the plant stems. Finally, treat your plant with one of the home remedies mentioned above. You can also spray the stems of your plants with neem oil (which you can buy pre-diluted or dilute yourself).