Why Is My Pilea Growing Mold?

For most of us, the sight of mold is bad news. We’ve learned that mold can cause a lot of problems, both to homes and to the people living in them, and that as soon as we notice even a little bit of mold forming, we have to clean, scrub and attack it with bleach. And while that’s generally a warranted response in case of black mold, when it comes to mold around your Pilea, there’s no need to panic.

Mold on houseplants can be found at soil level or burrowed deep inside the soil. However, if you notice a talc-like substance that looks like mold on top of the leaves, that may be powdery mildew. (Don’t worry, we wrote a post on that too.)

In the case of mold, what you’re seeing is the presence of saprophytic fungi which feed on dead or decomposing organic matter. Under certain conditions, the fungi reproduce quickly and form an extensive mycelium network. This is usually harmless, unless you’re allergic or suffer from asthma, but some people consider it unsightly.

Why is there mold in my Pilea pot?

There are a few common causes why mold takes over your plant’s soil.

1. You’ve bought very active and fungus-heavy potting soil.

And this is not a bad thing at all. If your soil is rich in organic matter, especially bulky pieces such as coco coir or bark, it’s bound to have some fungi spores burrowed in it. That means there’s plenty of broken down matter for your plant to feed on. But it also comes with the undesired side-effect of sprouting something to life every now and then - whether we’re talking about mold or the occasional mushroom.

Remember that fungi spores are everywhere - in the air, on the ground, on items that we bring into our homes - so it may also be possible for spores to land on your potting soil and find a good environment to reproduce even if your potting soil is not the culprit.

2. You’re watering too much.

What exactly is a good environment for mold? In a nutshell: soggy (soil) and stuffy (air).

When your soil is rich in fungi, these have a better chance of taking over if the soil stays too wet for too long. Damp soil, especially indoors, can lead to the rapid growth of mold inside the pot. This often happens in the colder months, when Pilea is going through a period of dormancy and it doesn’t need to take in as much water. This also coincides with the absence of sunlight around our plants, which also creates an auspicious environment for mold growth.

Here’s a more in-depth guide to the best watering practices that will keep your indoor plants thriving.

Another factor that causes excess moisture is poor drainage. Make sure your potting container has good drainage holes (preferably spread across the diameter of the pot, not just one hole in the middle). Drain the water from the catchment saucer and never let your Pilea stand in a puddle after you’ve watered it.

3. Your Pilea needs airflow.

Stagnant air around your plants (often coupled with overwatering) can increase the risk of your Pilea being surrounded by mold. When we want to improve airflow, we have to think of the surface area above the soil line as well as what’s going on in the soil itself.

To improve air circulation above ground, place your Pilea in a well-aerated spot that doesn’t get direct draft. And while it may be tempting to put your Pilea in a corner out of the way, inside a hutch or on top of a cabinet, just make sure that there is enough air movement around it to help the soil and the leaves remain dry.

You should also pay attention to soil aeration, especially if your Pilea has been planted in the same pot for a while. If the soil is compacted, meaning it has very few air pockets, your plant’s roots won’t be able to access oxygen. But it also means there won’t be enough airflow to help the soil dry out after a thorough watering session.

Aerating your Pilea’s soil isn’t hard and you don’t need any special equipment to do it. Just gently insert a stick in the soil every 1-2 inches and loosen it up a bit to create some air pockets. But please don’t use sharp items such as knives or skewers which might damage the root structure.

Ideally, you should aerate the soil before you water your plant. Aeration will help the water distribute evenly and it will dislodge clumps of soil that have stuck together and solidified.

What should I do if I notice mold around my Pilea?

The easiest thing to do is nothing. Nothing about the mold, that is. However, you have to do something about your environment:

• you have to adjust your watering schedule (water less frequently, let your Pilea dry out between watering sessions and only water when the top two inches of soil are dry to the touch).

• you have to adjust the airflow: manually aerate the soil and move the plant in a spot with better air circulation.

According to the RHS, the type of mold we get on our houseplants is generally harmless for most people (though we’re not mold experts), but it may be more than a nuisance for people suffering from allergies and asthma.

Even though the mold itself is generally harmless, the conditions that have led to the development of mold may indicate long-term problems yet to come. This is true especially if you have a pattern of overwatering your Pilea. Too much water for too long can put your plant at risk of root rot, which is very hard to recover from.

If you want to remove the mold, then you should start with an in-depth inspection of your plant. To make this step easier, do it before you water the plant. The dry soil will make it easier to inspect what’s going on below soil level.

Hold the pot with one hand, and gently pull out the Pilea (holding it by the stem) with your other hand. What do you see? Have pockets of mold formed in the soil, or is the mold just covering the surface?

If there are no visible pockets of mold in the soil (white, yellow or light-green patches), then you can put the plant back into the pot. Afterwards, scrape the top 25 percent of the soil off the top, discard it, replace it with fresh potting soil, and give it a good watering.

If you notice mold below the surface level and in more than one spot, then it would be a good idea to give your plant a soil refresh. Gently remove the soil from around the root structure and give the roots a good rinse. You can reuse the same planter, but you should give it a quick rinse in soapy water. You should then repot your Pilea plant in fresh soil and keep in mind our previous advice: rein in the watering.

To sum up, moldy soil is no reason to panic. And you definitely don’t need to toss out your Pilea. Mold is a relatively common occurrence in the life of plant parents. Do your best to keep it under control and always err on the side of underwatering your Pilea, especially in the cold dark months.

Disclaimer: At Pilea, we are houseplant enthusiasts, but we are not mold experts. Please do your due diligence and consult an expert if you want to know more about molds inside your home.

Keep Reading