I’ve got several small houseplants in my home office, and I really like having them around. I’m still pretty new to taking care of them altogether, though, and we’ve gotten dozens of tiny house gnats now. I’ve put up sticky traps and tried to use some pest control in the potted soil. But would a small venus fly trap be able to help here?
Apple cider vinegar in a bowl with a drop of dish soap will be a lot more effective.
Isn’t this more for fruit flies? I tried something similar for fungal nats and was unsuccessful. What worked for me was yellow sticky pads and letting plant soil dry out almost completely between waterings.
This is the best plan. They are prolific breeders so traps are useless if you don’t also eliminate the favorable breeding environment.
Ha! I was just typing up a comment about the same thing and only saw yours after I submitted mine. Yours is much more clear and concise. I suck at brevity, lol.
No, not really. My VFT catches gnats but I don’t think it would effectively reduce them overall.
Good to know! I was really hoping someone out here would have first-hand (leaf?) experience. Thank you!
I’m going to agree with them. I had one as a kid and while I didn’t ever see it catch a gnat I can pretty much guess how it would go.
They’ll snap shut at the lightest touch so you get one maybe two gnats in there and it shuts. Then, at least with mine IIRC, they always took 30 minutes to an hour to reopen even if they didn’t catch anything.
I also don’tthink they’d keep up but, depending on how many gnats you’re seeing, and how many VFTs they might. They are cool as hell though so honestly it ain’t gonna hurt to try.
There are a few practical management steps you can take as well to help reduce the gnat load.
Sand (washed playground sand as an example) as a mulch layer over the top of the potting mix will drain quickly and removes the gnat’s preferred habitat for egg laying.
Bottom watering, while admittedly slower than pouring from the top, also helps to reduce the amount of time the top layer of soil is wet enough for them. Allowing the potting mix to dry thoroughly between waterings improves the efficacy of this practice.
I knew about sand but not bottom watering! Thank you for the info!
I don’t know that they’d be able to keep up with them, like the other commenter said.
Something that’s always worked a treat for me is to mix up some apple cider vinegar, some dish soap (I think they call it fairy liquid or washing up liquid in the UK?), and a little bit of sugar. I usually use a mason jar and put a little over an inch of apple cider vinegar in, then add the rest and stir it up. The vinegar and sugar attracts the gnats and the dish soap helps keep them from being able to escape once they touch the mixture. It works really well and I always find way more gnats in there than I even realized I had, lol. If it’s a big space, I’d put a few scattered around.
It does smell like vinegar, though… but I’ve found it’s worth it. It completely took care of the issue a few different times (until they’re introduced again, but there’s a lot of gnat-free time in between for me.)
I’ll definitely give this a try, thank you! It’s incredible how many there are
There are a few plants that would help with your savage garden desires.
Check out pitcher plants for example. These plants use a pitcher of nectar water to attract bugs who get stuck and slowly dissolved in the water - any captured flies act as fertilizer for the plants.
Alternatively look up “sundew” plants - They are essentially leaves with sticky “dew” that catches bugs which land on the surface of the leaves (and slowly absorbed the fly - some varieties will even curl up around the bug to digest it faster)
Both of these plants grow best in a “bog planter” (imagine a mini swamp on your desk) - with a tray of water constantly full to keep the soil “damp” at all times. I ended up 3D printing my own bog planters for my pitcher plants. My Sundew died, but I need to buy another one - I enjoyed growing them.
Oh this sounds like a lot of fun. I’ll have to look into these!
Pro tip, you need to use reverse osmosis purified water. They are very sensitive to chemicals and tap water will kill them quickly. If they are not a tropical breed, you will need to toss them and the seed in the fridge over winter to keep them alive and allow them to flower the next year.
I assume by pest control in the soil, you mean diatomaceous earth?
+1 for the apple cider vinegar / dish soap thing. That and diatomaceous earth was enough to get them under control for us. Also make sure you don’t have water standing under the pots if you have those little dish things - we found one of them had backed up and a bunch of water was under the pot.
I do have those little water dishes. I’ll check those out to see if I’ve got any standing water. Thank you!
You mentioned pest control in the soil - have you tried mosquito bits? I ended up mixing some in with the soil for a Monstera and I also put a layer over the top and it does seem to make a difference. I do have to combine it with those unsightly yellow sticky traps, though. Between plants and the inverts I keep, my house is full of containers of damp dirt.
In case anyone is thinking about getting a katchy, you can read the reviews, but I give it a thumbs-down. I used it only a few times before fall and it worked okay, but when I pulled it out again in the spring I just get orange error lights and no response when I reached out to them.
My partner does all the stuff mentioned by other posters; bottom watering, mosquito bits solution, a carnivorous plant with sticky leaves.
Still have gnats!
One thing I have seen her use are sticky gnat traps
[Like these](Effective Fruit Fly Trap - Yellow Sticky Traps for Gnats and Plants - Get Rid of Fruit Flies with Gnat Sticky Traps - Perfect for kitchens, patios, picnics https://a.co/d/1e1qeC1)
They are the only thing I have seen that cuts down on them.
