Soil Has White Mold: Tips for Growing Beautiful Houseplants

Are you enthusiastic about gardening? Perhaps you cultivate your own produce, or maybe your interest lies in nurturing ornamental plants? If you affirmatively responded, you undoubtedly recognize the considerable care and affection required to maintain their appealing and robust health.

When it comes to the “enemies” of plants and the soil, mold, precisely white mold, is the issue owners often have to deal with. This looks like white stuff on the soil that is growing.

White mold is a fungus called Sclerotinia that thrives on the soil used in potted plants. This is usually because inadequate drainage and poor air circulation cause damp and humid conditions. It is the perfect environment for white mold to grow.

What Plants Get Moldy Soil?

Mold, or sclerotinia, is a fungal disease affecting over 360 different plants, such as beans, lettuce, pea, and brassicas, which are cabbage family members. This can be a struggle for the gardener in their garden. So is white mold on soil bad?

House plants are also affected by moldy soil due to their conditions. In the case of mold affecting tomatoes, it is known as timber rot.

White mold on soil in a potted plant

Mold symptoms are noticeable on blossoms, leaves, pods, stems, and soil. Leaves will eventually wilt, turn yellow, and die. And as for the pods, they may rot. Host crops are the most susceptible during flowering. However, young seedlings are at risk as well.

Mold usually infects the plants early in the summer or spring and, with time, keeps developing unnoticed for a while.

When the weather is cold, mold fungus releases spores that can be carried by the wind, infecting other plants. And that is precisely the reason why it is of crucial importance to catch mold as well as destroy infected plants in time.

How To Successfully Identify White Mold Damage

White fuzz on soil can vary based on the environment as well as the type of plant. However, there are some commonly displayed ones, such as:

  • At first, the stem may appear to have a water-soaked part. And at this point of the infection, your plant will still have a beautiful appearance; looking healthy above, it is tough to detect already occurred damages.
  • Wilting of stems, especially at the base, is accompanied by tan discoloration. Pay close attention as Infected stems may have tan to dark brown lesions.

And from these lessons, you will most likely find a dense, almost cotton-like growth of mold forming under high humidity conditions.

Control and Prevention of White Fuzzy Mold.

Is your potted plant soil turning white? The moment you notice any diseased plants, you need to destroy them immediately. Remove as much of it as possible to prevent soil mold infection and replace it with clean soil, especially in your garden.

You can try using a barrier such as mulch or plastic to cover the infected ground to prevent the spread of the disease.

Other methods to control white mold

Proper Watering

A soggy potting mix invites problems like saprophytic fungi (a mold) and may even lead to more severe issues such as root rot which will kill indoor plants.

Proper watering ensures the plant gets the necessary water without leaving the soil in excessively wet conditions.

To prevent mold, you must only water your houseplants when they genuinely need it. As a rule, you should water them in 6-inch pots whenever the soil is dry at 2 inches. Smaller pot plants should be watered whenever the soil is dry at a depth of 1 inch.

Keep adding water slowly and carefully until you notice it running out of the holes in the pot’s bottom. As for the excess water draining from the pot, you should discard it promptly to avoid mold spores germinating.

White mold on soil

Cleaning Up Plant Soil Mold

Houseplant soil mold in most cases, you can try scraping the fungus or mold from the potting soil surface and placing the plant pot in a suitable, well-ventilated area to ensure that the soil will dry.

If you notice that the mold returns or, in another case, the soil remains soggy, try repotting the plant using fresh and sterile potting soil.

And remember that before using the plant pot again, ensure to soak it in a solution consisting of 1 part household bleach and nine parts water for approximately 10 minutes.

Proceed by scrubbing it with water and dish detergent. This will kill off all mold spores that remain.

Prevent white mold with adequate drainage.

Even the best watering technique in the world won’t prevent white fuzzy mold in soggy soil if your pot can drain freely. This can even cause white fuzz on plants too.

For proper drainage, every plant container needs to have holes in the bottom with the container sitting on a removable saucer to ensure it will catch the water while it keeps draining from the plant pot.

Additionally, you can try placing bits of broken crockery or a layer of small pebbles in the bottom of your pot to prevent plant soil from becoming saturated. If in doubt, add more drainage holes.

Improving the drainage while preventing bits of the plant’s soil from ever clogging the holes again. This is especially important if the containers are in the rain in your garden, as it is easier for mold to form. Improving drainage will help prevent mold on plant soil.

Normally, a 6-inch pot needs 1 inch of pebbles, and a 12-inch container requires a minimum of 2 inches. Always check the holes periodically to ensure they aren’t blocked.

What potting soil should I use to Avoid White mold and Fungus

Nothing is worse than coming home to notice a white fungus on the soil of your plants. Carefully choose a good quality sterile potting soil containing a mixture of composted plant material like bark, white perlite or sand, and peat moss. This will help prevent white fungus/mold on your soil

Potting soil sometimes contains other materials, but these three ingredients function as the basis of the potting soil, which can support the plant, helping with draining freely.

But ensure your potting soil is clean and free of insects and pathogens like fungi. It is easy to detect contaminated potting soil as it usually has white strands and a sour smell. This soil should not be used as it is likely to contain mold spores.

Open bags of moist potting soil often function as breeding grounds for mold, insects, and microorganisms, so sealing the bag before storing the unused portion would be wise.

Remember that even the best potting soil can last only a year or two. And once it begins breaking down, it can not manage water well. Therefore, the soil will end up retaining too much moisture.

To prevent that, try repotting your plants every two or three years to refresh the soil while improving drainage and reducing the likelihood of mold forming.

If you start to see white cotton-like strands, this is the beginning.

Suppose you do not want to remedy the mold issue alone. In that case, you can still eliminate the problem with one effective, proven method – repotting your plant in fresh and sterile soil, ensuring that the old contaminated soil will no longer exist.

Repotting the plant after a white mold outbreak

If you have a mold outbreak, try removing your houseplant from its pot, cleaning the container, and then refilling it with fresh and sterile soil.

Alternatively, try soaking the container in the bleach solution mentioned above to thoroughly remove any remaining mold spores.

Afterward, proceed by rinsing the plant pot out with regular dishwashing liquid and water. And once the plant pot/container has dried, you can continue filling it with soil and repotting the houseplant.

Before replanting a houseplant, if you find mold growing on indoor plant soil, rinse the root system (the roots should be white to brown) and clean the mold off the leaves. In case of any remaining mold spores, you may end up with decontamination.

So spraying the plant with a fungicide before repotting it is better. This will destroy mold and mildew spores.

After you have repotted the plant, you must ensure that you can entirely prevent mold growth by adopting an efficient watering and care routine.

Killing white mold with a fungicide

If your plant is contaminated with mold, it will further damage the new soil, contaminating it as the white mold grows, especially in damp conditions. You can start by removing the mold by hand. Use a damp rag soaked in the bleach solution to wipe the white filaments of leaves and stems.

Typically, plant soil mold is only found on the surface, so you can try gently scooping the top layer of the damaged, contaminated soil out of the pot. However, Potho’s white fuzz will be on the plant’s leaves.

The next step for further protecting the plant and soil involves applying a fungicide to a plant. Suppose you do not like the idea of buying a chemical fungicide and instead prefer considering more natural options for dealing with mold.

In that case, you can use Potassium Bicarbonate mixed with water to eliminate mold.

This organic fungicide works efficiently with white mold spores, and spraying this solution over a plant as well as on the surface of the potting soil is enough to ensure health conditions.

SB Plant Invigorator is also an excellent product for killing mold, This is an organic soap, and I buy mine from Amazon.

Protect houseplants with an anti-fungal spray.

In some cases, the soil may need a helping hand to keep mold and fungus at bay. It may seem difficult at first if you live in a damp or cold area, but adding a natural anti-fungal to the soil can significantly help the situation.

There are several excellent natural anti-fungal options available to kill mold. Some great ones include apple cider vinegar, cinnamon, and white baking soda. Cinnamon is also great for removing ants and other potting soil pests. That’s a bonus tip for you.

And rest assured, none of them will ever harm the houseplant, provided you do not overuse them.

You can try mixing these into the soil or sprinkling them on top of your houseplant’s soil. However, ensure not to overdo it, as putting too much can harm the soil but help prevent white mold.

A couple of sprinkles or several spoons per houseplant is enough, so keep these amounts in mind. Neem oil or SB Plant Invigorator is perfect for killing white mold fungus, and the video below, although made for controlling pests with these products, will show you how to use them.


As can be seen, there are many effective ways to kill mold and ensure that your plant and the soil will no longer be bothered by mold.

And by implementing these methods while caring for your plants, you’ll be certain that they will stay in both beautiful and healthy conditions, enriching your surrounding environment with beauty and harmony with no mold.


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