I've been struggling with a fungus gnat invasion in my upstairs living room where I keep my 7 plants. I've been dealing with this for about a year now and have tried multiple methods to get rid of them, including using Mosquito Bits, bottom watering, and setting up sticky traps along with a UV light. While some traps catch a few gnats, they keep returning, and none of my efforts have effectively eliminated them. I particularly dislike bottom watering due to its appearance, but it seemed the most successful. Can anyone share their experiences or tips to finally get rid of these pesky gnats?
6 Answers
It sounds like you might be overwatering your plants. Fungus gnats thrive in consistently damp soil, so cutting back on watering can really help. It’s often better to underwater than overwater. Letting the soil dry out a bit could be key in getting rid of those gnats! Also, make sure each pot has good drainage, as larger pots can retain moisture longer, which contributes to the problem.
Have you considered using diatomaceous earth? Just sprinkle it on top of your soil and mix it in lightly. It can help eliminate fungus gnats by causing damage to their bodies. It looks a bit messy at first, but it’s been a game changer for me! Just be cautious not to breathe too much in while applying it.
Totally agree! I’ve seen good results with food-grade diatomaceous earth too, just be careful with the dust.
I finally beat my gnat problem by letting my plants spend the summer outside in the sun and rain. It really helped clear them out. I did lose some smaller starter plants to root rot along the way, but now I think I've got it under control for the ones inside!
Try adding a bit of hydrogen peroxide to your watering routine. Just a little mixed with water can help kill off any gnat eggs in the soil! Make sure you find the right amount to use; too much can harm plants, but it can definitely work against those pesky gnats if used occasionally!
The UV light works wonders! If you can make the room dark and leave the light on near your plants nightly for about two weeks, you might see a significant drop in the gnat population. This approach has helped me a lot, especially since I seem to attract flies from the nearby farm.
You’re on the right track, but just remember that treatments like Mosquito Bits take time. It might help to rotate different methods. Keeping sticky traps up and bottom watering could also help. It’s definitely a process, but stick with it!

Yeah, if the pots are too big, it can make it even harder to manage the moisture levels!