How To Get Rid of Mold in Houseplant Soil - Backyard Boss
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How To Get Rid of Mold in Houseplant Soil

Have you noticed a layer of white mold building up on the surface of your houseplant soil? While it is an unsightly addition to your beautiful greenery, it can also be a sign of other issues. Thankfully, the mold itself will likely not harm your plants and it is easy to remove. But, it’s better to be safe then sorry!

With the right tools and knowledge under your belt, you can easily clear your plants of mold and prevent it from returning. You can also try combining the two different ways of removal for even better results.

Tools You’ll Need

Soil to repot indoor plants
Image credits: Iryna Imago via Shutterstock

To properly remove and prevent mold build-up in houseplant soil, there’s a few tools you’ll need.

  • Well-draining houseplant soil
  • Pot with drainage
  • Hand trowel
  • Gardening gloves
  • Anti-fungal treatment
  • Watering can
  • Bleach
  • Stiff brush
  • Dish detergent
  • Warm water
  • Sharp scissors

What Causes Mold in Soil?

a houseplant in a pot from waterlogging of the soil and lack of fresh air is covered with mold, selective focus
Image credits: Korostylev Dmitrii via Shutterstock

Usually, mold in soil is a saprophytic fungus, which feeds on decaying organic matter in soggy soil. From there, it’s easy to find out what type of issues this mold results from!

First off, contaminated soil that is reused from old plants or uncleaned, dirty pots can carry mold spores. On top of that, if you’re accidentally overwatering it can result in a layer of mold because of stagnant water. Watering too often, poor draining soil, or a lack of a drainage hole in the pot can cause this.

Unfortunately, this mold comes with friends. Mold on houseplant oil can lead to other issues as it serves as a food source for pests such as fungus gnats. These pests can spread diseased spores from plant to plant as they move around your home.

Note: Remember that a white layer or crust on the surface of houseplant soil can also be fertilizer or salt build-up. This can be a sign of over-fertilizing. Avoid this by rinsing the plant with clean water from the top every four to six months and cutting back on fertilizing.

Two Ways To Get Rid of Mold

Getting rid of mold is super easy! You can use one of these two methods, or try them in conjunction with one another. Afterwards, learn all about keeping that pesky mold away.

Method 1: Repotting

Repotting and cultivating aromatic herbs at home. Hands in gloves holding fresh green basil plant with roots and soil on background of empty pot and rosemary plant on wooden floor. Horticulture
Image credits: Bogdan Sonjachnyj via Shutterstock

One way to remove mold from your plants is to repot them. Begin by removing the plant from its pot and inspecting the roots. Black or mushy roots are dead from root rot and you should remove them with sharp, clean scissors. Then, fill the pot with fresh soil and gently remove old soil from around the plant’s roots with your hands.

Replant the roots in the fresh soil, topping with more soil. Remember to use a pot with a drainage hole. In the future, check the soil before watering. Some plants prefer moist soil while others can dry out, but the soil should never be soggy or sopping wet.

Method 2: Hand Removal

Transplanting Nolin into new soil. Close-up on Nolin.
Image credits: Marvelous World via Shutterstock

You can also remove and discard the top layer of growing media with a hand trowel or fork. This option is better if the soil is not soaked and you think your plant is doing alright. You can also sit the plant in sunlight to help the soil dry out faster and keep it out of a humid location, such as your bathroom.

If the mold returns, it is best to repot the plant in fresh soil. Before you use the pot again, it is important to clean it since it can be contaminated with mold spores. To clean the pot, soak it in one part bleach and nine parts water for 10 minutes. Then, scrub the pot using a stiff brush with dish detergent and warm water. Allow it to air dry.

Preventing Mold in Soil

houseplants in flowerpots by sprayer
Image credits: Dikushin Dmitry via Shutterstock

Once you have removed and treated the mold, it is crucial to determine what caused the issue in the first place. If you were overwatering the plant, remember to follow proper watering recommendations and consider the temperature and humidity levels as well as the plant’s preferences.

You can keep humidity low by ensuring circulation and airflow between plants. For better drainage, use well-draining soil and maybe opt for a terracotta pot.

You can avoid contaminated soil by repotting new houseplants as soon as you get home, using fresh soil. Finally, you can prevent the issue by adding an anti-fungal treatment, such as hydrogen peroxide, to your houseplant soil.

Mold Be-Gone!

While mold on your houseplant soil doesn’t look great, it is very easy to get rid of. With that said, it can result in pesky gnats, which you may also need to treat. Plus, it is a sign that you need to change something about your houseplant care, whether that’s the soil and pots your plants are in or how often you water. In the end, prevention is key!

Do you have any tips for removing mold from houseplant soil? Share in the comments below!