What Are Those White Crystals on My Pilea’s Leaves?
Ewww, what is this white thing dotting the underside of my Pilea leaves? Is it a bug? Is it a disease? Is my Pilea sick? What am I doing wrong and should I throw away my plant?
That’s a common question we get that is usually accompanied by a picture of a perfectly healthy houseplant whose only sin is … being a houseplant. We totally get it. We understand that, especially for new Pilea owners, every single imperfection or deviation from the norm brings about some plant anxiety. Don’t worry, we’ve got your back.
What are we talking about?
When you see white salt-like crystals on the underside of your Pilea leaves, that means the plant is working as intended. The crystals are mineral deposits that are being released through the pores of the leaves when the plant transpires
Is my water at fault for the white spots on my Pilea?
Some people panic when they see the spots, and blame it on the hardness of the water in their area. They then switch to using bottled water in an attempt to avoid the white spots, but end up wasting money and too much plastic in the process. We don’t think switching to bottled water is necessary. And if you have, you may have noticed that the white spots haven’t disappeared. The crystals are a side effect of the plant’s water intake, and they’re completely harmless.
Should I remove the white spots on my Pilea?
Yes, you can. But you don’t have to. Once the crystal reaches a certain size, it will fall on its own. You’ve probably had a few fall already without you noticing. You’re neither helping nor hurting the plant if you remove the crystals. If you choose to remove them, gently brush them off with your finger, a soft cloth or a makeup brush. Please be gentle when you do so because rubbing them off might cause mechanical damage to the plant (in the form of scratching). Mechanical damage does heal, but it doesn’t disappear.
The spots also fall if you wash the leaves under a stream of water too, so you can remove them as part of your monthly plant cleaning routine. (You do have one, don’t you?)
How do I fix the white dots?
Again, there’s no need to fix this, as there’s nothing wrong with your plant. However, if you’re noticing that the plant develops crystals in rapid succession, it may be a sign that you’re overwatering. Ah, the eternal problem! Here’s what you can do:
Here’s a simple explanation of how our common enemy - overwatering - is also at fault in this case. Just like people, plants use transpiration to eliminate water from their system and keep themselves cool. In the cold months, transpiration decreases and the water absorbed by your Pilea’s roots exceeds the water lost through the leaves. So if you don’t adjust your watering regimen, the plant is forced to try to expel more water than it’s physically able to. That’s when the water gets trapped in its pores (stomata) and bursts out in the shape of white small crystals.
This can also happen in warmer months in places with high air humidity.
Try reducing the frequency of your watering sessions. And while you’re at it, remember to empty out the standing water in the catchment saucers after you have watered your plant.
Another reason why your Pilea develops mineral crystals faster than normal is if the water coming out of the stomata doesn’t get a chance to evaporate fast enough. Sometimes, it’s because we have placed the plant under a growth tent which doesn’t allow for the air to circulate. It could also be because air circulation is poor around your plant. Pilea plants dislike stale air just as much as they dislike drafts.
To improve air circulation around your Pilea, you can place it close to an open window (but not directly in front of it), or close to a spot that gets more fresh air. Avoid surrounding it with objects or other plants that cocoon it in a spot with no airflow.
Do not use oily substances on your plants.
Don’t oil your Pilea’s leaves with neem oil or coat it in mayo to give it a nice luster. We’ve touched upon this weird old tale in this post, and we also give you better alternatives to clean your plant. Basically anything that will clog up the stomata is bad news for your Pilea.
Use well-drained potting soil
Your potting soil needs to be adapted for indoor use and contain some sort of lighter material (pumice, perlite, coco coir). Check out our guide to the qualities and characteristics of good potting soil.
The minerals from the fertilizer will accumulate in the soil and gradually lower the quality of your mix. If you choose to fertilize your Pilea, always read the instructions on the bottle and err on the side of diluting your fertilizer more than the recommended amount. Never fertilize in the cold and dark seasons when the plant is dormant.
Drench your plants
This means putting your plant under a strong jet of water and oversaturating the pot until water gushes out through the drainage holes. This helps leech out some of the salts that have accumulated in the potting soil. Leave the plant in a place where it can drain out all the excess water (your sink or bathtub) for about 30 minutes before you return it to its usual spot.
Now you know the cause of those unsightly white crystal dots on your Pilea and how to fix them. They’re not harmful, we promise, so don’t sweat it too much.