I never thought I’d be a plant parent. I used to find houseplants very daunting, and anytime someone gifted me a plant, it would die under my care — yes, I killed the cactus my best friend gave me for my birthday.
Then I met my partner. When we first got together, she had nearly 10 houseplants she doted on. And ever since we’ve started living together, that collection has grown to nearly 20 — I never thought I’d say this — I’ve become a plant mom.
It’s always been my dream to own and nurture a monstera deliciosa (commonly known as a Swiss Cheese Plant), so we bought one that had just one leaf from an independent plant store a year and a half ago. We named her Fudge, as we name all of our houseplants. Fudge was thriving, popping out leaves with fenestrations every so often… and then tragedy struck.
I spotted a few tiny flies, which I later realized were fungus gnats, buzzing around her lush leaves and in her soil — and I panicked. I immediately texted one of my best friends who works on a gardening magazine and asked her for advice. She walked me through it, and I did some research, spending way too much time on r/monstera. Et voilà, Fudge was free of fungus gnats within a month.
If your monstera is struggling with a fungus gnat infestation, let me walk you through what I did — and hopefully, your monstera will be sprouting new leaves within no time, just like Fudge.
Wait, where did the fungus gnats come from?!
I won’t lie, fungus gnats are nasty and gross. These tiny flies aren’t harmful to humans or otherwise healthy plants, but if you have a baby houseplant, they can seriously damage the root system.
Fungus gnats appear when the top layer of your soil stays moist for long periods, and they’re attracted to the organic-rich environment of the soil. If you’re overwatering your plants, chances are you’ll attract a few fungus gnats.
Once they appear, they start breeding, laying eggs in the plant’s soil (yep, gross), and they multiply like crazy. The larvae munch on the roots and, like I said, can severely damage your plants. So you see why I freaked out? Fudge, our monstera, is very precious to me. We grew her from scratch and I’d be damned if I let anything happen to her.
Also, if you don’t get rid of fungus gnats promptly, they will spread to other houseplants. Trust me, I speak from experience.
To get rid of fungus gnats (again, so gross), you need to kill the problem at the root (pun not intended) — you need to destroy the foundation.
Fungus gnats lay eggs in your plant’s soil, and there are a couple of things you can use to kill them. The first thing you need to do is grab a bag of mosquito bits.
Mosquito bits contain BTI — Bacillus thuringiensis serotype israelensis — which is an organic larvicide, and you can buy a big bag for $14 / £24 at Amazon. While you’re waiting for your order, remember to isolate your infested plant. Like I said, fungus gnats spread quicker than you can imagine.
After Amazon promptly delivered the bag of mosquito bits the next day, I made what’s called a “tea.” I don’t know how many times I can say this but again, vile. I then soaked four tablespoons of bits per 4.5 litres of warm water, and kept them soaked for 30-60 minutes. Then, I used a strainer/sieve to separate the bits from the water. These bits contain corn, so if they find their way into your plant soil, they will mould.
I then watered the top layer of my monstera’s soil and let it soak through. I used the solution every 4-5 days until I was sure I’d killed the larvae.
Catching the strays
While the mosquito bits are working on killing the larvae, you need to get a pack of sticky fly traps. Even if you kill the larvae, the step would be moot if adult fungus gnats are still flying about because they’ll just lay more eggs (this is going to make me throw up). Sticky fly traps are bright yellow, and fungus gnats are attracted to that, so adult ones will fly right at them and get stuck to the glue.
I’d recommend grabbing a pack of 36 sticky fly traps, available for $9 / £4 at Amazon. Yes, you’re gonna need a few. After I bought mine, I stuck a couple in our monstera, Fudge-y, and two each in every other plant that was in her vicinity when this problem started.
The morning after, I was disgusted to see how many adult gnats were stuck to the sticky fly traps. But hey-ho, I had actually gotten rid of most of them over the span of 30-odd days!
Giving the plant new soil
To ensure that I had gotten rid of all the fungus gnats and to ensure our monstera had a healthy, thriving environment, I also decided to change her soil. I ordered a bag of repotting mix for just £8 at Amazon U.K. I took our monstera to our balcony, carefully pulled Fudge out of her original soil (keeping the moss pole/stake intact), and wore a pair of gloves to separate the oil from her massive, healthy roots.
While I was doing this, I noticed there were still a few fungus gnats crawling at the bottom of her pot and flying around in a frenzy, trying to escape. One of them flew into my mouth. Yes, that happened, and I still haven’t recovered because a) gross, b) disgusting, and c) ew. I’ll wear a mask next time (but hopefully there won’t be a next time).
Anyway, I washed our monstera’s roots with warm water and then placed her in a new pot and added the repotting mix to it. I quickly and easily did this, then watered her, cleaned her leaves, and misted them. I placed her in my home office, away from the other houseplants, to control exposure and give Fudge time to recuperate.
A week later, I spotted a new leaf growing on Fudge, which was a sign that she was healthy and happy and getting enough sunlight. I haven’t spotted a fungus gnat around her since, but if it does happen again, at least I’ll be prepared.
It all paid off, and in the end, I did it all for under £40 — but I’d easily spend as much as needed to ensure our monstera’s health and safety. Yes, I am a very protective plant mother. Never saw this coming, but man, does talking to my plants and looking after them fill me with unbridled joy.
Have any of your houseplants ever gone through a fungus gnat infestation? How bad did it get and are there any tips and tricks you’d like to share? Let me know in the comments!