4 Steps To Get Rid Of Fungus Gnats

Fungus gnats. The bane of any houseplant-lover's existence.

I've gotten rid of them once before, but then I was infested with them again, and it took a different tactic to get rid of them this time, so I thought I would write a little post with some tips!

1. Don't use Miracle Gro potting soil

this photo will be explained in #4

Nobody seems to know if they come in Miracle Gro soil or if they just like it because they put those water-retention beads in there, but either way - MG soil is NOT your friend. When I first heard this tip, I had currently been using MG soil so I opened up my bag and yeah ...it was crawling with them. I threw it out, and never bought it again.

2. Water from underneath

You can use proper aqua globes (blown glass bulbs with long stems), or you can just upturn narrow-necked bottles like I did in this photo into the soil, but either way, it will water the roots of your plant but leave the top part of the soil dry. This is important because the fungus gnats lay their eggs in moist soil, so if you let it dry out, the eggs don't hatch and eventually they die off.

3. Flush your sink drains with baking soda & vinegar

In addition to the damp conditions of your houseplants, they also like the damp conditions of your sink drains - especially if you have an overflow hole, like some bathroom sinks or the tub have, because they can lay eggs in there without being washed away every time you turn on the tap. So flush out those drains with baking soda and vinegar, then chase it with some hot (or even boiling) water. Alternatively, you can pour some cleaner straight down the drain too. Whatever will detach their eggs from the sides of the drain.

4. Apple cider vinegar traps

Here's my new one. I had heard of using ACV as a trap before, but honestly, they will commit suicide in any standing water at all - my cup of water, Yuan's bowl of water, the dirty dishes soaking in the sink - so I thought, they're already trapping themselves, that seemed unnecessary. However, this time I had a new situation: I have a moss terrarium that I had to keep damp, and they set up camp in there with a vengeance. You can see how brown it was getting in that photo, and I was at a loss as to what to do to get them out once they had gotten in. So finally, I took a little scoop from an old protein jar and put a little homemade ACV in there so it was extra juicy. Then I put plastic over the top and sealed it off for several days (see the first photo in this post).

I don't have a clear lid for this jar that I use as my terrarium, only a cork one (see below), so I normally take that on and off so the sunlight can get in, and yeah, a plastic bag to try and keep in moisture. But it wasn't sealed-sealed when the cork stopper was off, so the little buggers had gotten in!

After a few days, I opened it up to water and check things out. Carnage! There were not only dead gnats in the ACV, but even more dead and quite stuck to the plastic, that had gotten trapped up there in water droplets (told you they commit suicide in any water they can find). I couldn't even rinse them off; I threw out the plastic and put a new one in place, and rinsed out and replaced the ACV.

Since doing this, I went from seeing them all over the apartment, driving me crazy, and finding them dead in the aforementioned any-standing-water-available, to having seen I think two in the whole past week. I'm going to give the drains another flush now that the mothership of gnats has been taken care of, and that should be the end of it! Hooray!!

I hope this helps you get rid of any gnats you have setting up shop in your houseplants. :)