Terracotta pots are made from clay which is naturally porous. As such, they allow air and moisture to pass through their walls. This is very beneficial to plants that don’t like excess moisture around their roots such as cacti and succulents. However, these pots are prone to mold.
The formation of a white fuzzy mold on terracotta pots is not only unattractive but also unhealthy for your plants and family. In this guide, I’ll explain why mold may grow on your terracotta pots and what you can do to get rid of this dreaded fungi.
What does mold on terracotta pots look like?
White mold is a powdery fungus that thrives in dark and humid conditions. It’s a common household problem that can also affect your indoor plants. Despite its name, white mold can also appear dark, grey, or green depending on the surface that it’s growing on.
White fuzz on plants or terracotta pots is one of the telltale signs of mold. It can easily be mistaken for mineral deposits or the natural weathering of the pot material. However, mold will come off easily when you scape it with your finger and mineral deposits will not.
Note that, mold can be very unhealthy for humans and pets. The fungi produce spores which can easily be inhaled. This can be a problem for people with allergies or asthma. So when dealing with mold, wear a protective face mask to avoid direct contact.
White fuzzy mold on terracotta pots causes
The porous nature of terracotta pots can provide a perfect breeding ground for mold. Its porous nature allows water from the soil to linger and this encourages the fungi to thrive. Keeping your potted plants in a dark or poorly ventilated area can make the fungus grow even faster.
With lower light, the rate of photosynthesis declines. As a result, plants take up less moisture from the soil and this makes the pot remain damp for longer. This also means, watering your plants too often can encourage the growth of mold in your houseplant soil and pots.
Mold spores are easily spread through the air, water, or by contact. If you have other plants with mold nearby, it can quickly transfer to your terracotta pots. Weakened or stressed plants are always more susceptible to mold and other fungal diseases.
How to get rid of white fuzzy mold on terracotta pots
There are several ways to remove mold from terracotta pots. The first step is to temporarily isolate the affected pot to prevent the spread of spores to other plants. Place it in a sunny, well-ventilated area to discourage further growth and spreading of the mold.
The next step is to treat as follows:
Clean with bleach solution
Bleach is good at killing mold on non-porous surfaces but it has also shown to be effective in dealing with mold on terracotta pots. Since it kills plants, you should remove your plant from the pot before treating it. To avoid inhaling toxic fumes, it’s best to work in a well-ventilated area.
Here’s how to use it:
- Put on protective gear (gloves, mask, eye goggles and old clothes)
- Mix 1 cup of bleach into 1 gallon of water.
- Pour the mixture into a spray bottle.
- Spray onto mold on the terracotta pot and allow it to set in.
- Gently scrub the surface of the pot with a stiff brush to remove the mold.
- Rinse the treated pot with clean water, then allow it to air dry for a few days before transferring the plant back in.
Note: Never mix bleach with ammonia or other household cleaners. When bleach is mixed with ammonia, a toxic gas called chlorine is produced. Inhaling it can potentially cause severe health problems.
Use 3% hydrogen peroxide solution
Hydrogen peroxide is the safest option for treating mold on your planters. It’s completely non-toxic and safe to use around plants, humans, and animals. That means you don’t need to remove your plant from the pot when treating for mold.
Simply pour 3% hydrogen peroxide into a spray bottle and apply directly on the pot’s surface. You’ll notice some sizzling as it acts on the mold. Let it sit for 5 to 10 minutes and wash the outside of the pot to remove the spores. If needed, scrub the outside of the terracotta with a hard brush.
Apply baking soda solution
Baking soda is another natural and safe ingredient for killing mold. While it’s safe to use around humans and pets, baking soda is toxic to plants. This means before you use it on your terracotta pots, it’s best to temporarily transfer your plant to another pot.
Combine 2 tablespoons of baking soda with 2 cups water in a spray bottle and shake until it’s completely dissolved. Spray the solution onto the mold and let it sit before scrubbing. Afterward, rinse your terracotta pot and allow it to fully air dry for a few days before putting it in the plant.
Call a mold remediation company
If you suspect that the problem of mold in your home is far beyond your control, call a mold remediation company for professional help. They have the proper equipment for detecting and removing mold and all spores anywhere in a speedy and efficient manner.
How to prevent mold on your terracotta pots
Mold can be difficult to control but with good gardening practices, you can prevent its growth on your terracotta pots.
Provide good drainage
Although terracotta pots already have good drainage, using well-draining potting soil can further prevent water from accumulating on the surface. As you know, mold thrives in damp conditions and they love it when you keep overwatering your plants or growing them in poorly draining soil.
The easiest way to prevent mold on your terracotta pots is to water your plants moderately particularly when the soil feels dry. Additionally, make sure the pot has drainage holes where excess water from the soil can escape. This will also prevent the problem of root rot.
Ensure proper ventilation
Good ventilation is key when growing plants indoors. Proper airflow around the plant stops moisture from settling on your pots and this greatly reduces the chances of mold. If your room doesn’t have some venting windows you may consider running exhaust fans when humidity is high.
Provide adequate lighting
As I said earlier, mold spores thrive in dark, warm, and humid conditions. If your plants receive adequate sunlight as needed, it becomes difficult for mold to thrive on your terracotta pots. Further, with good light, plants photosynthesize more and in the process, they use more water.
Clean your pots regularly
Regularly clean your terracotta pots to remove any dust or debris. These are organic materials that may provide a foothold for mold. A simple scrub with water and a brush can help to extend the life of your pots and prevent the growth of mold.
Mold on terracotta pots can be a nuisance and a health risk to your plans and household members. However, with the right preventive measures and treatment strategies, you can keep your pots and plants healthy and mold-free. Simply maintain proper plant care practices, monitor the plants regularly, and act promptly if you spot any signs of mold.
United States Environmental Protection Agency – Finding Mold and Moisture
Washington State Department of Health – Dangers of Mixing Bleach with Cleaners
Centers for Disease Control and Prevention – Mold Cleanup and Remediation
My name is Diane M Lewik, and I am the founder of this website. I am a degree holder in plant biology from the University of California – Berkeley. Over years, I have cultivated a vast collection of succulents and I have learned a great deal about how to grow and care for these unique plants.