Mold On Plant Soil: What It Means And How To Get Rid Of It

Coming across white mold on your plant’s soil is a nasty shock, but it’s not as bad as it looks, and it is simple to fix.

As long as you don’t let the mold sit on the soil for too long, and you fix the cause, there is no reason to panic, as it won’t affect your plant too badly.

But what exactly causes mold on the soil? Do you need to use chemicals to get rid of it? What happens if you leave the mold on the compost?

Let’s take a look.

What Causes Mold On The Top Of Soil?

No one welcomes mold when it comes into your home, and it can be a little worrying to see it grow on the top of your houseplant soil.

Luckily, your gut reaction is about the worst of it. Mold on soil is a natural thing – after all, the soil is full of living things, but it doesn’t exactly look nice, and it can, in some cases, harm your plant if you leave it there for too long.

As you probably know already, mold lives and spreads in damp places, just as shower curtains and bathrooms can get moldy, so can wet soil.

Let’s take a look at what can cause it.

Imbalance In Growing Conditions: Temperature And Light, Little Air Circulation

Think about the care you give your plant as a set of scales. Each element works as part of a whole: light, temperature, soil, air circulation, humidity, and if one or more of them are wrong, it knocks the rest out of balance.

If your plant is in too dark a spot, this can cause mold, as the light and warmth help get rid of excess moisture. 

Similarly, if there is plenty of humidity but not enough airflow, this will also cause mold. When you raise the humidity, you also need to improve air circulation, otherwise, things will get a little musty.

Dead Plant Material Sitting On The Top Of The Soil

If you let dead leaves, flowers, or stems collect on the soil instead of removing them, this can also cause mold to develop.

Poor Drainage

Having your plant in the wrong type of soil, in a pot that’s too big, or watering your plant more often than it needs will also cause mold on the soil.

Not Being Stored Properly

Mold can also start when the compost isn’t stored properly. If it’s not somewhere cool and dark, without any direct light, and sealed up properly, the mold can develop in the bag, contaminating the lot.

Should You Ignore Mold On Your Plant’s Soil?

Just as you wouldn’t ignore mold growing on the inside of your house, don’t ignore mold growing on the soil of your houseplants. Let’s take a look at how you should get rid of it.

How To Get Rid Of Mold On Soil

Remove The Top Layer Of Soil

Grab a dust mask, and some safety glasses if you have them. While mold isn’t usually something to worry about on soil, you don’t want to go inhaling the stuff or get it in your eyes, either.

Scrape off the mold with a clean spoon, or, using gloves that you can easily wash, remove the top layer of the soil with your hands, putting it straight into a trash bag you can seal immediately and put outside.

You shouldn’t need to repot the entire plant, just the moldy stuff, as mold usually grows on the surface, so replace what you remove from the pot with fresh compost.

How To Prevent Mold From Coming Back

Be Careful About Watering

If you’re a little heavy-handed with the watering regime, try to check the soil before you water, as this can be the difference between watering your plant properly and letting it drown!

Too much water will make the soil struggle to dry out, causing mold and even root rot. Always remember to tip out any excess water from the bottom of the pot, too.

Improve The Plant’s Conditions

Try to bring a balance in the plant’s growing conditions. Improve light levels, which will help with temperature, and put your plant somewhere that has better air circulation. 

Consider if your plant is in the right type of soil, too.

Top Dressing The Soil

Use a fine layer of horticultural grit or small pebbles over the surface of the soil, which helps lock in moisture without causing mold, as well as preventing pests.

Should You Treat The Soil With A Fungicide?

No, as chemicals can harm the good stuff in the soil such as beneficial bacteria and microorganisms, and once they’re gone, they won’t come back.

If you want to treat your soil with something, sprinkle a little cinnamon on the top, as this is a natural fungicide, but if you follow the tips above, mold will not come back.

Final Thoughts

Mold on your plant’s soil is easy to deal with, but it’s even easier to prevent by giving your plant the right conditions.

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