How to Remove (and Prevent) Mold Growth in Houseplants



Plants need water and nutrients to grow, but there are other things that might also use that “food” in the right conditions. Due to the nature of a plant’s life, they can be susceptible to mold growth. Mold is not necessarily a huge risk to the plant, although excessive accumulation of mold can eventually trigger issues for people who live around them. The main solution to the problem is addressing the mold promptly and taking steps to ensure that it does not come back. A balance of cleaning moldy soil and taking steps to prevent mold growth in the first place make it relatively easy issue for gardeners to solve.

Don’t Panic or Throw Out Your Plant

The good news is that mold is often not particularly harmful for plants. It does indicate something wrong with the plant’s environment or care, so gardeners should take warning. However, it may not be too difficult to solve the problem.

Houseplant Soil Mold Removal Tips

In order to remove mold from a plant, people should take care to avoid spreading it throughout the home. Since mold can be harmful to humans, the best way to start involves:

  • Wearing gloves, a dust mask, and protective eyewear
  • Taking the plant outside to a shady spot
  • Bringing a small scoop, shears, and paper towels

Once outside, people should find a place to sit and work. They can start by inspecting the plant for signs of mold growth. Wiping the leaves with wet paper towels can remove old mold. Leaves that are extremely moldy may need to be trimmed and discarded.

At this point, plant owners can inspect the soil. If the top of the soil is colored or fuzzy, using a spoon or small scoop (like a hori hori knife) may be easy to scrape off the top layer for disposal (and don’t forget to clean these tools before putting them away!). If there is too much mold throughout the pot, repotting may be a necessity. Otherwise, it is simple to add a fresh layer of uncontaminated soil and a fungicide to help keep the mold from coming back. Gardeners who do not want to use a commercial fungicide may want to consider ground cinnamon, which natural repels fungus.

What Causes Mold & How to Avoid Mold Growth in the First Place

Mold needs a dark and damp environment to grow, which is why people may have the worst problems located behind their walls. Under the soil, mold can grow if there is too much water, insufficient drainage, lack of ventilation, or contaminated soil.

Watering Too Much and/or Too Often

People who are new to gardening often struggle to find the right balance of watering for a plant. Part of this problem is that plants have preferences that will change depending on the region and their placement in a room. Plants that need more water outside in bright, direct light might not require as much in indirect light and a temperature-controlled space.

Plant owners who are unsure how much to water a plant should research watering recommendations based on the type of plant. Many guides suggest feeling down into the soil to determine how deep the dry soil goes, but this is more of a rough guess that some people may not feel comfortable with. Instead, buying and using a moisture meter might be an excellent way to determine the actual moisture level. That way, gardeners can add just the right amount of water at the right frequency.

Pots or Soil Don’t Have Enough Drainage

The right soil and pot combination depends on the plant, and drainage plays a big part in whether or not a plant can stay healthy. In cases where mold is showing up, plant owners should look for signs that the soil is getting soaked too often, appearing muddy. Soils with a lot of peat qualities, as well as soil combinations that contain mostly peat, contain much more water than soils with a lot of sand. Gardeners should consider using soil that is built to suit the plant, and consider changing pots if necessary. Adding a layer of gravel or LECA at the bottom can promote drainage without losing too much water.

Lack of Air-Flow or Ventilation Causing Excessive Humidity

Stagnant moisture is a common cause of mold or mildew development in the home, especially in areas that are meant to stay somewhat damp. The invention of air conditioning was chiefly made to handle humidity more than temperature. In the absence of air conditioning or other types of ventilation, humidity can get out of control. Gardeners may need to watch plants that need a higher humidity in particular.

Fortunately, ventilation is fairly simple to fix. For rooms that do not have a vent, people might want to add a ceiling fan or even a portable one that they can use to circulate air throughout the room. Aiming the current is important, as plants with air blowing on them constantly (from a vent or fan blade) may suffer from the constant draft. Positioning the fan to pull the air down from the ceiling is ideal to keep it circulating.

Contaminated Soil

Many gardeners like to use compost or mulch in their gardening to help preserve moisture and provide nutrients for the plants. Some even make their own compost to this end, although it takes care. Organic matter provides food for beneficial bacteria as well as food for fungi like mold. The problem is that people may not be able to tell that there is mold in the soil until they use it for a plant and identify the issue later.

Keeping the soil in planted pots clean, and taking care of extra soil are good ways to prevent contamination. Old compost that is not stored properly may start to grow mold. The same is true for soil that gardeners keep on hand without storing it in a dry, closed container. If people are not sure about the soil, replacing it is more likely to prevent the problem—but do make sure to try and take steps to conserve soil whenever possible.

Organic Debris

Organic debris fills a couple of requirements for mold growth. First, leaves that fall into the pot may obscure signs of growing mold, so that gardeners are not aware of it until it is a much bigger problem. Second, the organic matter provides a ready food source for mold spores, particularly if they are damp or soggy. Taking away fallen leaves or dead organic debris out of a planted pot once it falls addresses both concerns. Instead, these can be added to a larger plan to mulch the yard.

Should I Be Worried About Houseplants Bringing Mold Into My Home?

Mold can pose health concerns to humans, but mold on houseplants does not need to be a disaster. Most gardeners will identify the source and be able to address the causes long before the mold becomes an active issue causing headaches or respiratory issues. All that people need to do is to pay attention to their plants on a regular basis, and make sure they get the right amount of sun, water, drainage, and ventilation. Proper care will do the job of prevention better than addressing concerns later.

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