If you use terracotta clay pots for your indoor plants, you may have seen white stuff appearing on the vessel’s exterior.
Such white residue can be white mold or mineral deposits leaching out of the pots. It is essential to know how to determine whether the white stuff is mineral deposits or white mold on terracotta pots.
Mold growing on your clay pot can present serious health issues and harm your plant if it is present in the soil. However, it is harmless to the plant if confined to the outside of the plant pot.
White Mold On Terracotta Pots
Surprisingly, the clay material that these pots are crafted from is porous and allows air to pass through. Through its design, the pot allows natural salts and minerals in water to pass through it, creating an unpleasant white powdery accumulation on its exterior.. This residue is harmless and can be removed with ease.
What Is White Mold?
White mold is a blanket term for various types of mold that are white or whitish. These fungal growths can also be green, black, or grey.
However, they are all harmful and present health risks regardless of color.
White mold is easy to confuse with mineral deposits on terracotta pots because both substances have the same color.
While white mineral deposits (efflorescence) do not cause any harm, mold produces pores that can be harmful to people and plants.
So it is essential to identify mold and remove it as soon as possible for safety reasons.
And they are a common sight on terracotta pots because the porosity and moistness of these vessels make them perfect for mold growth.
But how do you differentiate between mold and mineral deposits on your clay pots? Let’s take a look below.
How to Identify White Mold on Terracotta Pots
If your terracotta plant pot has white residue on its exterior walls, the substance can be one of two things:
- Mineral deposits leaching out of the porous clay pot walls, or
- White mold
If the residue is accumulated mineral deposits, you may only want to remove it for cosmetic purposes.
The white stuff may be unsightly against the bright orange, red, or brown color of your terracotta pot.
Otherwise, salt and mineral deposits are harmless. They come from the combination of moisture, salts, fertilizers, and the chemicals in water inside the soil.
These substances seep out through the porous pot walls over time.
However, if the substance is mold, you must remove it as soon as possible to avoid the health risks associated with it. Mold can also kill your plant if it gets in the potting mix.
So how do you identify the white residue on your plant pot?
i. Start by studying the texture of the white stuff.
Give the pot a quick visual inspection to determine the texture of what you have. If the substance has a flat texture, more like dust on the surface, then your terracotta pot has nothing more than mineral deposits.
However, if the white residue is fuzzy with a noticeably raised texture, you are dealing with a mold problem. Use the tips later in this post to get rid of them and keep your plant and family safe.
ii. Put on a pair of gloves and use your hand to poke the white residue
Mineral deposits will feel somewhat crusty and hard on your hands when you touch them. In contrast, white mold will feel fuzzy and much softer to the touch. It will also scrape off the pot more readily.
iii. Observe the patterns that the white stuff has formed
If your pot has white mold, the residue should form small, circular patterns with more color concentrated around the middle.
Touching residue and observing its texture should be sufficient. However, you can still observe the patterns for good measure.
Other Mold Types
Mold can exist in various colors other than white. All of these varieties typically come in different sizes, shapes, and odors.
However, all mold types are dangerous and can cause allergies and other health complications.
Black mold is one of the most popular varieties. If your terracotta pot has this kind of mold, you will see black spots on the affected walls. This should stand out against the red or orange color of your pot.
While regular dirt or soil will cause the same discoloration, you can identify black mold by its fuzzy or fluffy soft texture.
Green mold appears as green discolorations on the affected surface. You should be able to identify it by its equally soft, fuzzy texture that scrapes off easily when you touch it.
While white molds are common on terracotta pots kept indoors, green mold may develop on plant pots kept outside.
Why Does White Mold Grow on Terracotta Pots?
Several common causes of mold growth on terracotta pots exist. Here is a detailed look at the factors likely to cause or promote this fungal growth.
i. Low temperatures and moist conditions
Mold requires moist conditions, air, and dirt to grow. Terracotta pots are made of clay, with their porous walls providing molds with excellent growth surfaces.
Water seeping out of the walls of your terracotta pot keeps the surface damp. Since these pots are usually sheltered from harsh temperatures to promote healthy houseplant growth, molds can readily take advantage of the conducive environment and sprout.
ii. High humidity
Since plant pots made of clay have porous walls unlike plastic pots, they can readily absorb water vapor from the air. In turn, this makes the walls soggy, creating a breeding ground for mold.
Therefore, white molds can be prevalent on terracotta pots located in humid environments around your home.
iii. Dark conditions or lack of proper sunlight
Molds prefer dark conditions for their growth. So if your clay pots are in areas with poor lighting, you may experience a mold problem.
The darkness will allow molds to grow and thrive, causing white deposits on your plant pots. Dim lighting does not work in isolation. Instead, it will contribute to mold growth alongside other mold growth factors like moisture and oxygen.
iv. Poor air circulation
Poor ventilation promotes mold growth indirectly. The limited air circulation usually leads to the buildup of humidity around one or a few pots.
With humidity comes condensation that, in turn, creates moisture settling on the surfaces of your terracotta pots. Once this happens, molds have a perfect spot to pitch a tent and survive.
Most plants require watering after the soil gets dry. However, if you water your indoor plants more frequently than you should, the soil remains wet for prolonged periods, and the excess water finds its way through the porous pot walls.
The excess moisture escaping through the clay walls creates damp conditions necessary for mold growth.
Such molds can quickly spread to spread to adjacent pots or other areas within your home. So it is crucial to deal with the problem as soon as you become aware of it.
How to Remove Mold From Terracotta Pots
Mold produces pores that can cause allergies and other health complications when inhaled. So it is crucial to get rid of them as soon as you become aware of them.
Here are the tried and true solutions to consider.
1. Use Neem oil and dishwashing solution.
If you are a plant parent, the chances are that you have used neem oil to kill pests on your indoor plants. The oil is a potent fungicide that kills fungi and pests by suffocation.
Mix one part neem oil with one part dishwashing liquid in a small bucket of water. Stir the solution thoroughly to mix, and then use it to clean the white mold residue.
Consider wearing rubber gloves when using this solution to remove molds from your terracotta pot. Use a sponge to scrub the mold off your clay pot, then rinse it with clean water.
2. Use hydrogen peroxide solution.
Hydrogen peroxide is one of the most effective solutions against fungi such as molds.
To use this fungicide, fill a spray bottle with 3% hydrogen peroxide solution and use the bottle to spray the solution to the affected area.
Apply the fungicide in circular motions until it has covered the entire pot.
Once done, let the pot sit for 15 to 20 minutes before scrubbing and wiping the dead mold with a kitchen sponge. You could also use a toothbrush to scrape the fungi off your pot.
Ensure you safely dispose of the sponge or toothbrush used after completing the exercise.
3. Use bleach solution
Bleach typically consists of a diluted sodium hypochlorite solution. Mix one part bleach solution with 20-part water in a spray bottle and apply it on the affected clay pot.
Once you have mixed the solution well, spray it on every inch of the pot, including the parts without the white residue.
Bleach is such a strong chemical, so you may want to take out the plant from the container and keep it somewhere safe or in a temporary pot until after cleaning the affected pot.
After removing all the white residue, clean the entire pot with clean water before replacing the plant.
4. Clean it with baking soda.
Baking soda is a mild mold killer that you can use to safely get rid of the white mold on your terra cotta pot. Unlike strong chemicals like bleach, baking soda can kill molds on the pot while the plant is inside.
It also has deodorizing qualities, so it can effectively eradicate mold odors while simultaneously killing them.
Start by creating a baking soda paste by adding a little water to baking soda in a bowl. Mix the product gently into a paste.
Next, use a toothbrush or other similar tool to apply the paste to the mold, covering all the white areas. Leave the baking soda on for about 20 minutes to work on the fungi before scrubbing and rinsing with clean water.
How to Prevent White Mold in Terracotta Pots
While the methods discussed above will help you eradicate white mold on terracotta pots, mold growth can recur unless you deal with its root cause.
Here is how to keep molds away from your clay pots.
Avoid overwatering your plants
Overwatering keeps your terra cotta pots wet for prolonged periods. This prolonged wetness encourages and sustains mold growth.
Therefore, ensure you cut back on watering your plant, allowing the soil to dry completely before adding water. This way, the plant will utilize the water better, leaving little to escape through the porous walls of the pot.
Ensure proper sunlight access
UV radiation from the sun is highly effective in killing and preventing mold. Keeping your plant where it receives adequate amounts of sunlight per day will discourage mold growth and keep your terra cotta pots mold-free.
Proper sunlight exposure is an excellent mold prevention method because it does not involve the use of any harsh chemicals that could reach and harm your plant.
Ensure proper drainage
One way to keep moisture from seeping through the terra cotta pot walls is to give it a way out. Create proper drainage holes at the bottom of the pot to allow excess water out.
Doing so will reduce the likelihood of excess water escaping through the clay pot walls and keeping it wet enough to support mold growth.
Keep the humidity in check
Humid conditions breed molds and encourage their survival. The water vapor in the air condenses and settles on the pot, keeping it moist and highly conducive for molds.
Keeping the humidity in check should help keep the pots dry and mold-free.
Ensure good air circulation
Consider using fans or AC to improve the ventilation around the plants. This will help reduce the chances of atmospheric water vapor condensing on the terracotta pots.
Can I Leave the Mold on the Terracotta?
Leaving mold on terracotta pots is not recommended. Mold produces spores that can easily become airborne.
Touching or inhaling these spores may cause allergic reactions and other serious health complications, such as asthma attacks.
The fungi can also get into the soil inside the pot and kill your plant.
Can You Pressure Wash Outdoor Terracotta Pots?
We do not recommend pressure washing terra cotta pots because they are fragile. The pressure from the high-power water jet can break the brittle pots, especially if they have stayed outdoors for a long time.
How do you get rid of white mold on plant pots?
The most effective way of eradicating white mold on plant pots is by using 3% hydrogen peroxide. Put the liquid in a spray bottle and use it to spray the exterior of the affected plant pots. Allow the fungicide to work for about 20 minutes, and then scrub away the residue and rinse with water.
Why is mold growing on my terracotta pots?
Mold grows on terracotta pots mainly due to dampness. This dampness can result from overwatering, poor air circulation, high humidity, and poor drainage.
White mold on terracotta pots can come when you least expect it. However, as long as you know how to identify and kill these fungi, you can stop them from spreading onto other surfaces and wreaking havoc in your home.
If you have a mold problem, consider using the guidelines in this post to fight them and prevent them from recurring.
We hope this guide helps you out. Let us know your thoughts in the comments.
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