Diagnose, Treat and Prevent: The Secrets to Eradicating Mold on Pots

Gardening can be a beautiful and rewarding experience, but it’s not without its challenges. One of those? Fighting off mold on your plant pots!

Mold growing on terra cotta pots, clay pots, and other planters can seem like an unsolvable problem, but with the right tools, techniques, and preventative measures, you can grow your beautiful indoor garden again in no time.

So let’s get down to it! In this blog post, we’re going to uncover the causes of mold growth on clay pots and go over ways you can treat and prevent this issue from occurring in the future. Ready? Let’s get started!

white mold

What is mold, and what are the health risks associated with it?

Mold is a type of fungus that is found in plant soil and air, and it can grow on your terracotta pots if the conditions are right.

While it isn’t necessarily dangerous, mold produces spores that can cause a variety of health issues, including allergic reactions and respiratory problems, which can be especially dangerous for those with asthma or a weakened immune system.

In addition, mold spores can spread from your terracotta pots to other areas of your home, exacerbating the problem. To prevent mold from taking over your plant clay pots and spreading throughout your house, it’s important to take some preventive measures.

What Causes Mold Growth on Terracotta Pots?

Mold is a type of fungi that thrives in moist environments and can quickly take over a terracotta pot that isn’t well-ventilated.

There are a few different things that can cause mold to grow on terracotta pots:

Poor Drainage

Poorly draining soil can trap moisture, leading to mold growth. If the pot is too large for the plant, excess water will pool in the bottom of the terra cotta pot and provide an ideal environment for mold to grow.

After watering your plants, it’s important to drain the terracotta pots so that the excess water can escape. If you don’t do this, the water will continue to pool in the bottom of the pot and provide an ideal environment for mold spores to grow.

Watering too often

While watering your plants is vital to keep them healthy, overwatering can also lead to mold growth on the pots. If you water your plants too often, the soil will stay constantly moist. These are ideal conditions for mold spores to take root and start growing.

Using the wrong type of pot

Some types of pots, like terra cotta, are more prone to mold growth than others. Terracotta absorbs moisture due to its porous nature, which can create a conducive environment for mold.

Reusing Pots

Reusing the same pot over and over can also lead to mold growth. This is because old terracotta pots can have embedded spores that will start growing when exposed to moisture. You may not see mold spores on the surface of the pot, but they can still be present.

Soil that goes bad

Even if you’re using the right type of terra cotta pot and watering your plants correctly, mold can still grow. Old or disinfected soil can harbor mold spores, which will eventually find their way to the surface of the pot.

How to identify mold on your plants and terracotta and clay pots

mold spores

Mold can be difficult to identify because it comes in many different shapes and sizes. Generally speaking, you will most likely see a white fuzzy mold or a black mold on the surface of the clay pot. White mold is usually caused by excess moisture, while black mold can be caused by a variety of factors, such as poor drainage or using old soil.

However, this can be difficult to spot as, in some cases, white mold and mineral deposits can look similar.

So how can you tell if your plants have been infected with white mold or are just dirt or mineral deposits?

To tell the difference, try scraping a bit of the substance off with your fingernail (covered in glove) and see if it is moldy or just soil. You can tell that by its sponginess and smell.

  • Salt and mineral deposits will be hard and crumbly, while white mold will feel spongy.
  • Mineral deposits will not have a distinct smell, while mold will often have an earthy or musty odor.
  • In contrast to the mineral deposit, the white mould layer is usually noticeably thicker and raised.
  • The colors of mineral deposits typically vary between white and yellow.
  • White mold’s growth is circular, while mineral deposits follow a more irregular pattern.

So, now that you know how to identify mold on your plants, what can you do to prevent it?

How to clean mold and disinfect your plant clay and terracotta pots

fungal growth

One of the most important things you can do for your plants is to keep their pots clean. While it’s important to disinfect your clay pots on a regular basis, mold can still build up, especially on terracotta pots.

Here’s how to kill mold off your pots:

Using White Vinegar

White vinegar is a natural disinfectant and can be used to clean mold off your clay and terracotta pots. To use, mix equal parts of white vinegar and water in a spray bottle. Spray the mixture onto the affected area, and leave it to sit for 15-20 minutes before wiping it down with a damp cloth.

Baking Soda

Baking soda is another excellent way to get rid of mold on your clay and terracotta pots. Mix one part baking soda and two parts water until you have a thick paste. Apply the paste to the moldy areas, scrub gently with a brush or sponge, then rinse with warm water.

Hydrogen peroxide

Hydrogen peroxide is a great way to naturally disinfect your clay and terracotta pots. Mix one part hydrogen peroxide solution to three parts water, then spray the solution onto the affected area. Allow it to sit for a few minutes before wiping it away with a damp cloth.

Make sure not to expose hydrogen peroxide to direct sunlight, as this can cause the solution to break down.


For more stubborn cases of mold, try using bleach diluted with water. Mix 20 parts water to one part bleach, then spray or pour the mixture onto the affected area. Allow it to sit for a few minutes before wiping it away with a damp cloth. Before applying, you should take the plant off the pot and remove any soil. After the mold is gone, you should soak the pot in water to remove the remaining bleach and allow it to dry before replanting the plant.

What can you do to prevent mold growth on your plants

Mold readily grows

While it may be challenging to completely get rid of white mold on your plants, there are some steps you can take to help prevent it from occurring in the first place.

  1. Proper Potting and Drainage: Ensure your pot is large enough for the plant and has proper drainage holes. Overpotting can lead to too much soil staying wet, and this moisture can create an ideal environment for mold growth.
  2. Appropriate Watering: Avoid overwatering your plants and water only when necessary. Allow the top inch or two of the soil to dry out before watering again.
  3. Air Circulation: Good air circulation helps keep moisture and humidity from building up in the pot, so make sure your plants are not too crowded.
  4. Cleaning: Clean your terracotta or clay pots regularly with a mild soap and warm water solution. This will help remove any build-up of dirt, debris, or mold lurking in the soil. Additionally, you can use a diluted bleach solution (1 part bleach to 10 parts water) to disinfect the pots.
  5. Use a Sterile potting mix. It also helps to mix some perlite or gravel into the soil before planting, as this will help increase drainage and reduce moisture retention. Lastly, ensure you only water your plants when necessary and never overwater them.

For terra cotta pots, coat them with a sealant to protect them from moisture. This will create a barrier between the pot and any water that may seep in. The sealant will also help keep away mold spores.

Following these tips can help keep mold and other fungal issues away from your plants. With a little bit of effort, your plants can remain healthy and happy!


Should I throw a moldy pot away?

No, you do not need to throw away a moldy pot. Instead, follow the steps above to clean and disinfect the pot before replanting your plants.

What happens if you touch plant mold?

In some cases, touching mold can cause an allergic reaction. Additionally, certain molds can produce toxins that can be harmful if ingested or inhaled. It’s best to wear gloves when handling moldy clay pots or soil and wash your hands thoroughly afterwards.

Does sunlight stop mold growth?

Yes, direct sunlight can help reduce mold growth. When possible, move your plants outdoors or to a sunny spot inside your home to help keep mold at bay.

How can you tell the difference between mold and mildew?

Mold typically appears as fuzzy, dark spots, while mildew often looks like a white or gray powdery substance. Additionally, mold has a musty odor that can be detected when you are near it. Mildew does not typically have an odor.


Although mold is a natural part of the environment, it can also be harmful to your plants and your health. By being able to identify mold on your plants and taking steps to get rid of it, you can keep your plants healthy and free from this pesky fungus.

Photo of author
Passionate about urban gardening, indoor growing solutions, and sustainability. Believes in growing our own food and eat fresh and better food by getting back to basics, growing a fruit and vegetable garden, and cooking from scratch.