BY THE OPTIMIST DAILY EDITORIAL TEAM

Keeping houseplants is a very satisfying hobby, but sometimes problems develop that make even the most experienced plant parent nervous. Mold on the soil surface of your plant is one example of such an issue. The good news? Usually, there’s no need to worry! Mold on houseplant soil is a common problem, but with a few simple measures, you can remove it and keep it from coming again. Let’s look at ways to keep your plants healthy and your soil mold-free.

What does mold on houseplant soil look like?

Mold on houseplant soil often appears as little to big patches of fuzzy white stuff on the surface. You may also see it around your plant pot’s drainage holes. Although this may be unattractive, it does not necessarily indicate that your plant is in danger. However, if left unaddressed, mold can indicate underlying problems that could negatively impact your plant in the long run.

Why does mold grow on houseplant soil?

Even the healthiest houseplants can occasionally get moldy soil. Mold spores are omnipresent, and when the right conditions arise, they settle and thrive. The appearance of mold suggests that some environmental factors may need adjusting to effectively maintain your plant. Here are the most typical causes of moldy soil:

Overwatering

Overwatering is one of the most common causes of mold on houseplant soil. When the soil remains damp for an extended period, mold spores may flourish. This problem is most frequent during the cooler months when plants grow more slowly and the soil takes longer to dry out.

Poor drainage

If your plant’s pot does not have adequate drainage, water gathers in the soil, promoting mold growth. Mold thrives in environments with high moisture levels and low ventilation.

Contaminated potting soil

Mold can sometimes originate in the soil itself. If your potting soil was exposed to moisture during storage or was not adequately packed, mold spores may have been present when you planted your houseplant.

Is mold harmful to houseplants?

Mold on houseplant soil is often not dangerous. The white, fluffy mold is most likely a saprophytic fungus that feeds on decomposing organic waste. In fact, these fungi can aid in the decomposition process by helping the soil cycle nutrients.

However, mold can compete with your plant for nutrients, and its presence often indicates moisture problems. Overly moist soil can cause greater issues like root rot or attract pests like fungus gnats, so it’s better to handle the mold before it spreads.

How to remove mold from houseplant soil

Now that you understand why mold grows on soil, let’s talk solutions. Here are some effective strategies for removing mold from your plant’s soil:

1. Scrape off the mold

If you find mold early, the simplest solution is to scrape off the top layer of infected soil. Allow the leftover soil to dry slightly before adding dry potting mix. Going forward, make sure you don’t overwater the plant.

2. Use natural fungicides

For a natural solution, dust the soil’s surface with cinnamon, which has antifungal effects. Another approach is to combine baking soda and water and spray the soil with the solution. If natural remedies don’t work, you can buy a commercial fungicide at a garden center.

3. Repot the plant

If the mold is extensive, it may be time to repot your plant. Remove the plant from its container, discard the moist, moldy soil, and replace it with new and well-drained potting mix. To prevent future mold growth, ensure that the new pot has sufficient drainage.

Preventing mold on houseplant soil

Mold is always easier to prevent than to deal with after the fact. Here are some ways to keep your plant’s soil mold-free and healthy:

1. Avoid overwatering

Always check the moisture level in your plant’s soil before watering. A reasonable rule of thumb is to water only when the top inch or two of soil appears dry. Plants require less water during the cooler seasons, so adapt your watering practices accordingly.

2. Improve soil drainage

Using a well-drained potting mix is essential for preventing mold. Adding perlite or sand can help aerate the soil and allow excess water to drain. This will also make your soil less susceptible to mold spores.

3. Select the right pot

Your plant’s container should include drainage holes to let excess water out. If you prefer ornamental pots with no drainage holes, consider placing your plant in a plastic nursery pot within the decorative one. To water the plant, remove the plastic container and return it only after the excess water has drained away.

4. Increase air circulation

Poor air circulation can cause moisture buildup, which promotes mold growth. Make sure your plants have enough space between them to allow air to circulate freely, and consider using a small fan or dehumidifier in particularly humid sections of your home.