Flush all the pots with a solution of one part 3% hydrogen peroxide to 4 parts water. Do this when you would normally water the plant anyway. The peroxide will kill off the gnat larvae without harming the plant. But you will still need to address the flying adults...I'd suggest using some yellow sticky traps for that. Adults only live for about a week so it shouldn't take long to get things under control.

And if you top your pots off with a layer of coarse sand or gravel, that will discourage the adults from laying their eggs there.

And no, they are not inevitable :-) I have never had a fungus gnat infestation with any of my houseplants but then I tend to underwater them to the subsistence level. Overwatering is the biggest cause of most houseplant issues.

thank you gardengal! I’ll make sure I am better about using a “tell” instead of my finger... I feel like I let them get really dry but maybe I need to push the envelope more... even my two zz plants which have been watered once in two months are completely infested despite letting it dry out ... perhaps I have it in too big of a pot so I am overwatering one of them. I just watered it the other day and ever since then the gnats have been horrendous... so I won’t use hydrogen peroxide on that one yet since I just watered... but I will do it on my other plants when they need to be watered. I Guess I’ll use neem oil in the mean time. I’ll try the sticky tape as well

thanks again!!

If you would like a 100% effective method that will kill larvae & adults completely, try Bti ( Bacillus thuringiensis subsp. israelensis ). It's a type of bacteria that only affects gnats & mosquitos and will wipe out fungus gnats in a home completely. 100% harmless to humans & other animals. It's a fully organic biologic control.

You only need a few drops in a quart spray bottle of non-chlorine water (you want to keep the bacteria alive & help them grow). A 2 oz bottle will last for many years for houseplants. One example is Microbe Lift Mosquito Control by Ecological Labs. You can get it online or in pond supply stores. Spray the soil of your plants, the leaves, and any window sills where they congregate. While hydrogen peroxide may work fine up to a point, you wouldn't want to combine these methods because the HP might kill the beneficial bacteria before they got to work.

Thank you Tom H! I will definitely look into that!

I'd just like to reiterate what gardengal said. Fungus gnats are not inevitable. Like her I've never had a problem with them and I think it's down to not overwatering. I gauge by the appearance of the plant and the weight of the pot whether water is needed.

I agree, floral. I've only ever had them at the end of winters where I gave the plants a little too much "attention". I've also only had them when using mixes with fine bark. Haven't had them at all since using blonde peat as my base.

Yes thank you all for your input! glad to know they are not inevitable and that I can take steps to keep them out of my house. I will work on diligently giving my plants “less attention“. like I said, I feel like I don’t overwater but I will push the envelope even more to see if that helps solve my problem. Now that I have more plants it’ll be even easier to divide my time and not fuss over one or two particular plants.

On another note, I use soil pep (5), perlite(1), and Canadian peat moss (1) for my mix. Does that sound appropriate? More specifically the soil pep. It’s a 3/8 minus screened bark. I know everyone tends to use their own specific mixture of soil so no worries if you can’t answer that for me :)

thanks again! I appreciate all of your input so much!

HI Tom!

I bought some mosquito bits. It’s says they are made of BTI... do you think it would work for me to soak the bits in water and then spray my plants and other surfaces that are infested with gnats? I put some bits on top of the soil for when I water as well so hopefully that’ll help.

Also, I made a bunch of my own soil and I think Something I used in my mixture had fungus gnats cuz when I repotted any of my new plants suddenly had them. Perhaps it was a coincidence... either way is it appropriate to “sterilize” soil by baking it? I read that doing some research but I was curious if it was really helpful or hurtful..

thanks all!