Identifying White Mold on Terra Cotta Pots (And Cleaning It) - Lovely Houseplants (2024)

Even though plastic and ceramic pots are becoming hugely popular with houseplants owners lately, terra cotta (clay) pots are still loved by many due to their classic look. While many manufacturers attempt to replicate the look of a terra cotta pot with different materials, it just doesn’t quite have the same feeling.

Aside from the aesthetic look that we enjoy, terra cotta pots have benefits such as allowing water and air to move freely through their walls that directly benefit your plant by reducing the risk of problems such as root rot.

That being said, terra cotta pots aren’t without problems either. Due to their porous nature, a common problem with terra cotta pots is the appearance of white spots. While these white spots can be salt and mineral deposits, they can also be a sign of white mold growing on the pot.

So, how can you identify if white mold is growing on your terra cotta pots?

While salt and mineral deposits (efflorescence) are often flat patches that feel solid when you touch them, white mold is slightly raised when you look closer, feels fuzzy, and has a different pattern where it grows in the form of circular spots.

As separating the two can be challenging by just looking, the easiest way to identify white mold is to wear a glove and touch it with your hand and see whether it feels fuzzy or not.

Since identifying the problem is the most vital step for finding solutions, let’s go deeper into how you can find out whether the white spots on your terra cotta pots are caused by mineral deposits or white mold.

Identifying White Mold on Terra Cotta Pots

Understanding whether the white spots on your terra cotta pots are a result of mineral deposits or white mold is no easy task, especially if you have never experienced such a problem in your life before.

As the necessary steps for resolving the issue depends on knowing the cause, we have laid out a few tips and tricks that will help you identify white mold.

• Start by taking a close look at the white spots. The appearance of both mineral deposits and white mold on the same pot isn’t unheard of, which is why you should analyze the spots first and see whether there are differences between them. While mineral deposits are usually flat (as if your pot got dusty), white mold has a fuzzy and raised look, which becomes even more apparent if it has grown big.
• Wear a glove and touch the white spots with your hand. Mineral deposits feel solid as they are completely dried out, similar to how salt would feel in your hand. On the other hand, white mold has a softer and fuzzier texture that is entirely different from how mineral deposits feel.
• Look for patterns around the pot. White mold usually grows in the form of small, circular spots that have a more concentrated color at the center. While this isn’t too conclusive, as heavy growth around the same area can make it hard to see this pattern, it’s something to keep in mind.

What Is White Mold and Why Does It Grow on Terra Cotta Pots?

Before getting to how you can clean white mold off, let’s talk about what white mold really is and why it grows on your terra cotta pots.

White mold is an umbrella term for different types of mold such as Cladosporium or Penicillium, even though it’s also possible for these types of mold to appear in colors such as black or gray. That being said, since all molds are harmful, identifying the type of mold isn’t very necessary for our purposes.

Due to its color, white mold is often confused with mineral deposits (efflorescence) or mildew. The key point to consider here is that while efflorescence and mildew don’t cause any harm, white mold can potentially pose health risks, which makes it essential to remove it as soon as possible to be on the safe side.

Just like any other type of mold, white mold also grows in moist areas. When you think about it, terra cotta pots are indeed a perfect place for the growth of white mold due to their porous nature. Considering that your pot is constantly in contact with a certain amount of water, mold growing at some point isn’t surprising.

While excess amounts of white mold are often caused by factors such as overwatering, lack of airflow, and lack of sunlight, white mold forming on terra cotta pots is often unavoidable if you don’t take extra steps to ensure that mold cannot grow.

Getting Rid of White Mold on Terra Cotta Pots

If white mold has already made its way to your terra cotta pot, you will need to clean it off.

Fortunately, with the right ingredients and some effort, cleaning white mold should be a breeze.

Removing White Mold without Removing the Plants

If the growth of white mold isn’t too severe, you can most likely salvage the situation by cleaning the spots that appear to be moldy from the outside without removing your plant from the pot.

The materials you will need for this process are white vinegar, water, a brush or a sponge, and a container such as a spray bottle.

1. Start by combining equal parts of water and white vinegar in your bottle.
2. Spray the vinegar and water mixture on the affected areas of your pot. While this mixture is harmless for your plant, refrain from getting in the soil not to disrupt the pH balance.
3. Spray the mixture on your sponge, and wipe the affected areas until the mold completely disappears.
4. Rinse the affected areas with water, and wipe them dry.
5. Spray the walls of the pot with the mixture, and let the mixture dry on the pot. Doing this will be helpful to get rid of the smaller spots of mold that may not be visible to you.

If you haven’t managed to get all the mold off, repeat the process by starting from step 2.

Deep Cleaning (Sanitizing) Your Terra Cotta Pot

In cases where the mold growth is too severe, removing it only from the walls of your terra cotta pot may not be sufficient. If the mold has spread to the areas that you cannot reach, it will just come back soon after you wipe it off the walls of your pot.

The materials you will need for this process are water, bleach, a container that can accommodate your terra cotta pot, a sponge or brush, and a pair of latex, vinyl, or nitrile gloves.

1. Start by removing your plant from the pot, and get rid of any excess soil in it.
2. Wear your gloves. As bleach can be quite harmful to the skin, ensure that you don’t touch anything bleach-related without wearing gloves first.
3. Fill your container with a mixture of 9 parts of water and 1 part of bleach.
4. Place your terra cotta pot inside the container that contains the bleach and water mixture.
5. Let your terra cotta pot stay in the container for 30 minutes to an hour.
6. While your pot is still in the container, scrub it thoroughly with your sponge to ensure that all the mold is gone.
7. After you ensure that you have scrubbed all the areas, transfer your pot into a container filled with water.
8. Once again, allow your pot to stay in the container for 30 minutes to an hour. As bleach is harmful to plants, it’s vital to ensure that there are no remnants of it in your pot before you put your plant in it.
9. With a clean sponge that hasn’t been in contact with bleach, scrub your pot thoroughly in the water.
10. Repeat the process starting from step 5 a few more times to ensure that all traces of bleach are gone.
11. Take your pot out of the container, drain any water that may be left inside, and let it dry.

Preventing White Mold from Growing on Terra Cotta Pots

While white mold growing on terra cotta pots is a commonly encountered problem, there are a few things you can do to prevent it from happening.

• Ensure that you aren’t overwatering your plant. A large amount of mold growth can be a sign that you are overwatering your plant. To understand whether the white mold problem is caused by overwatering or not, check for signs such as yellowing or browning leaves, wilting, or falling leaves on your plant.
• Let your terra cotta pot get some airflow. If you have placed your terra cotta pot at a place where it gets no airflow at all, moisture will build up and cause white mold to grow.
• Let your terra cotta pot get a sufficient amount of sunlight. If sunlight isn’t reaching your terra cotta pot, the moisture will not dry out and allow white mold to grow.
• Wipe the walls of your terra cotta pot with a mixture of white vinegar and water frequently. Doing so will keep your terra cotta pot clean and sanitized, reducing the risk for mold growth.

Wrapping Up

While white spots on your terra cotta pot don’t necessarily have to be white mold, it’s vital to identify the cause as soon as possible in the case that it actually is mold.

As long as you identify the problem before it becomes too severe, you can clean white mold easily without removing your plant from the pot, with simple household items that you probably already own.

Our best advice moving forward would be to frequently inspect your terra cotta pots and react as soon as you notice something out of the ordinary.