Why Is Mold Growing on My Clay Pot? (And How To Prevent It)

Clay pots are a popular option for growing plants, cooking food, and making tea. However, the qualities that make clay pots so healthy and good for people and plants are the same ones that lead to space for mold growth. 

Mold is likely growing on a clay pot because of moisture retention caused by excess water or seasonal increase in humidity. To prevent mold, ensure the pot has good drainage and ventilation. You should also glaze your pot. 

In this article, I’ll explain why mold grows on a  clay pot, how to prevent it, and the easiest ways to remove the mold growing on your clay pot, so read on!

Do Clay Pots Retain Moisture?

The primary reason for mold growth is moisture retention. 

Clay pots retain moisture because clay is a microporous soil that gains flexibility when water is added. Its porosity allows water to seep through, and the water then evaporates or flows out flowy from the surface.

Apart from clay’s natural ability to retain water, mold and mildew growth are encouraged by poor drainage in the pot, increased humidity in the environment, and a lack of proper ventilation. 

When all these factors combine, it can lead to a humid, organic environment perfect for mildew and mold growth. 

What Is the Difference Between Mold and Mildew?

There’s no difference between mold and mildew. In its early stages, a mold is called mildew — it appears like white, gray, green, or black stains on a surface. Fundamentally, mold and mildew are fungal organisms that grow on moist organic surfaces and break it down over time.

What Are Black Spots on Clay Pots?

Black spots on clay pots may likely be stains from fertilizers, impurities from the clay surfacing over time, or even the growth of fungi like mildew or mold. Unlike other stains, mildew and mold will have a fuzzy texture, which might be greasy but flat. 

How Do I Keep My Clay Pots From Turning White?


Clay pots may turn white for a number of reasons. 

You can keep your clay pots from turning white by first identifying the cause — whether the white color is due to mineral deposits, clay impurities, or mold growth. It’s best to glaze the pot or keep it sealed or cleaned with a fungicide if the white color is caused by mold.

Glazing Clay Pots Ensures They Become Resistant to Stains and Fungi

A glaze is a glass coating on clay surfaces that seals the clay, making it resistant to stains and fungal growths. Depending on the type of glaze, it can also be food-safe. 

Pottery can easily be glazed or reglazed as necessary, so even if your clay pot is old, you can take it to a potter to get it glazed. 

Ventilation Ensures Proper Moisture Circulation for Clay Pots

Improving ventilation in damp conditions is the best way to get the moisture circulating and prevent it from settling into the crevices of your clay pots. Ensuring good ventilation will stop mold growth and prevent your clay pots from turning white because of mold growth. 

Good Drainage and Correct Watering Will Prevent Mold Growth

Ensuring that your clay pot has a hole for excess water runoff goes a long way in preventing mineral stains and mold growth. 

Along the same lines, correct watering prevents your soil from turning soggy. The clay pots then absorb the excess water, leading to mineral deposits and moisture retention leading to mold growth.

How Do You Get Mold Out of Clay Pots? 

Getting mold out of clay pots is not difficult. There are several non-toxic ingredients you can use to remove mold from your clay pots. 

You can get mold out of clay pots by scrubbing the mold away using vinegar, hydrogen peroxide, or neem oil solutions. The other way to kill mold is to expose the clay pots to bright direct sunlight, immediately killing the mold. 

While bleach can be used to clean mold, it does not penetrate surfaces well, only disinfecting the surface. The roots of the mold remain, and the mold comes back stronger to fight against the effects of the bleach. 

Here’s a little more information on how you can use non-toxic ingredients for scrubbing mold. 

Spray Vinegar Solution on the Pot

Depending on the severity of the mold growth, you can use white distilled vinegar directly on the pot or mix it in a 50/50 concentration with water. Spray the vinegar or vinegar solution directly on the pot, sit for about an hour and wipe off.

Vinegar will penetrate the clay, kill the mold right at the root, and help prevent further growth of mildew, mold, or algae. 

Apply Hydrogen Peroxide Solution to the Mold and Let It Sit

A 3% hydrogen peroxide solution is a commonly used disinfectant; safe enough to use in contact lens cleaning solutions. 

The hydrogen peroxide solution should be applied to the mold and allowed to sit for some time. Then you can wipe it off.

Wipe the Mold Using Neem Oil Concentrate Solutions

Neem oil is an excellent fungicide that supports plant growth by removing mold. Preventing further mold growth and also preventing other fungi and insects that might attack the plants. 

Add a few drops of neem oil concentrate to a solution of dish soap detergent, and use the solution to wipe away the mold. You can watch Shaine Frolics With Foliage demonstrate this process on video on YouTube.

Leave Your Clay Pots Under Direct Sunlight

Bright, direct sunlight kills mold easily and quickly, so when you have a little bit of sun, you should set your pots outside. Sunlight will kill the mold immediately.

If you live in an apartment with a balcony, you can dry your clay pots on the balcony and ensure they have access to enough sunlight. But if your apartment doesn’t come with a balcony, you can always put your clay pots next to a window where sunlight can easily get through.

How To Clean Mold off Terracotta Pots?

Terracotta and clay are essentially the same; terracotta is simply clay after being fired.

You can use vinegar, hydrogen peroxide, or neem oil concentrate solutions to clean mold off terracotta pots. Or, you can expose the pots to bright, direct sunlight. 

Final Thoughts

Mold grows on clay pots because of clay’s porosity and moisture retention qualities. The best way to prevent this growth is by using glazed pots and ensuring good ventilation and drainage.

Mold growth on clay pots can be easily cleaned using non-toxic solutions of vinegar, hydrogen peroxide, or neem oil concentrate. Whenever possible, you place the pots in direct sunlight, which will help kill the mold.

For more, check out Do Plastic Pots Kill Plants? | Is It Bad to Grow in Plastic?

Anne James

Hi, I'm Anne but my grandchildren call me Jelly Grandma. I have over 50 years of experience as a Southern cook and am a retired librarian. I love sharing what I have learned. You can find me on YouTube as well! Just click the link at the bottom of your page.

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