Okay I have been battling these damn fungus gnats for way to long. I can trace it all back to some tainted soil from home depot. I completely repotted every plant in my home with better draining soil, mixing in some diatomaceous earth while I did it. I have sticky traps in all the plants and have only been watering with mosquito dunk tea. I have been cleaning all my drains, keeping the soil as dry as possible and I just can't get rid of them. Im to the point where I was just going to put all my plants in water and get rid of all the soil and get all new soil in a few months but I really dont want to go down that road. Light
by CardboardB0x
49 Comments
Try using nematodes – easy to get hold of via mail order and very effective against fungus gnats. The best nematodes to use are Steinernema feltiae
Look up peroxide and water mix. It has worked for me
Edit: Whoops you already had this going
Order Mosquito Dunks , its like a little concrete looking donut that you usually throw into ponds and still water to disrupt and kill mosquito larvae— and drop that in your watering can, let it soak. And use that as you normally water until bugs are gone— roughly 4-6 weeks. Aim to underwater a little. And you’ll see the next batch of buggies be smaller and weaker.
Alternatively: hydrogen peroxide mix 1:4 water
I used nematodes and it worked like a charm.
Mosquito bits/Mosquito dunks. Haven’t seen them in months! It kills the larvae and the adults are caught by the traps! Took around 2 weeks to see the results but I use ‘bits tea’ every few weeks as a precautionary
Gnatrol! Its been working great for me!
I spread DE on the tops of my plants and used sticky traps. The DE keeps the new ones coming up out of the soil. Essentially, they kill them while the traps are taking out the adults.
I put DE out a week ago. And there’s a noticeable difference already, but it isn’t immediate, no matter what you try.
Other options: get new soil, bake it in oven for 45-50 minutes at 350 to dry it out, killing anything in there, and then repot. This should be a part of your process with new soil since you don’t know what in there from the store, etc.
PLEASE, do not waste your time and effort with any of the internet remedies, that normally do not eradicate the problem completely. **Gnatrol** will rid them in one application. No fuss, no muss.
**Mosquito bits are designed for mosquitoes, not fungus gnats in houseplants. It is not the same as GNATROL, despite others who may argue the point.**
https://preview.redd.it/qyqhjftk39be1.png?width=824&format=png&auto=webp&s=e230f1e995043e3d7bca81527d939b5d94bc41d9
**THE** most effective solution is to eradicate in the soil at the larvae level. You need to **DRENCH** the soil.
**GNATROL WDG (Biological Larvicide**): [https://nufarm.com/usturf/product/gnatrol-wdg/](https://nufarm.com/usturf/product/gnatrol-wdg/)
**Gnatrol** is 100% safe for all plants and all other insect life, except fungus gnats. Accidentally used 3 tablespoons instead of 3 teaspoons per gallon, on a row of succulents in my greenhouse and didn’t harm a single leaf, but assuredly eradicated every single gnat.
How to Control Fungus Gnats in Indoor Plants: [https://deepgreenpermaculture.com/2021/02/16/how-to-control-fungus-gnats-in-indoor-plants/](https://deepgreenpermaculture.com/2021/02/16/how-to-control-fungus-gnats-in-indoor-plants/) – scroll down the article for practical tips on application.
Do NOT use neem oil! It will do more harm than good.
SMALL amounts can be purchased here: [https://www.organicbti.com/product-page/gnatrol-bti-omri-organic-fungus-gnat-larvicide](https://www.organicbti.com/product-page/gnatrol-bti-omri-organic-fungus-gnat-larvicide)
Have you tried honey and vinegar?
I had a bad infestation before. What helped me was diatomaceous earth plus mosquito bits. Now I don’t see any gnats.
I had a little old lady at Home Depot tell me a great trick! Use a thin layer of sand on the top of your soil. Worked like a CHARM! I struggled a ton as well despite similar efforts that you’ve been doing. This is what ultimately got them. And it doesn’t hurt the plants 😊
Also, if you keep your soil inside, don’t. I recently ordered a bag of organic succulent mix, and kept the bag in the shipping box in the front hall and forgot about it. Started having a gnat problem that I couldn’t get to the bottom of. Remembered too late about that bag of soil. Once I put it in a different container & moved it, the problem cleared up.
Scrape and discard the top 2 inches of soil. Make mosquito bits tea and top water. Wait 48 hours after top watering and sprinkle Bonide systemic houseplant insect control and top soil with pumice stone or zeolite.
Beneficial nematodes! Not gross at all, can’t even see them just throw sponge they send you in watering can. Easiest fix ever!
I’m not sure if this has been mentioned, but if you can, apparently fish tank gravel works wonders.
I put a layer of dry coffee grounds on the soil. It has to cover the soil completly and don’t water to often.
Lost Coast Plant Therapy…spray and water in to soil
Watch over-watering because they love wet soil. I put leca balls on top of the soil in my bigger planters like 1.5” thick and that cleaned up the problem for me
This is probably not helpful right now and could have been a fluke but I put my large money tree and monstera plants outside in the spring after trying the spray and sticky traps for several weeks. The gnats went away completely and I just brought them back in when it got too hot for them in the summer.
BTI drops are your friend
Small container with apple cider vinegar and a teaspoon of dishwashing liquid near the plant.
One inch compacted sand on top of the soil. Spray that daily with water with a little lavender oil in it. Killed every one I had.
I had very little success with Mosquito Dunks. BUT a two to three inch layer of sand on each of my plants solved the gnat problem without chemicals. The sand worked perfectly.
Couple teaspoons of dish soap to a gallon of water. Let the soil dry more in between watering. And if you really have an issue put and inch or two of sand on top of the soil to keep the adults from laying more eggs
I had the same issue with my plants and I was able to get rid of them. I stopped watering them to let the soil dry out and used this DIY remedy that I got from Almanac.com.
🟢 Cider-vinegar traps: Find a shallow container—a tuna can is perfect—and fill it with equal parts water and apple cider vinegar. (The liquid should be at least 1/4 inch deep.) Put a few drops of liquid dish soap into the mixture and stir gently. Place the trap near the base of the affected plant or, ideally, inside the pot on top of the soil. Check it every few days and refresh it with new vinegar and water.
I use a glass soda bottle and a funnel mix water and a little bit of apple cider vinegar and you have a nat trap. I keep mine under the counter for when I need it.
Get yourself a ping plant, aka Mexican Butterwort. The gnats will be no more.
I used mosquito bits and it got rid of them all. Would highly recommend!
What soil do you use? I found that after I switched to only using [fox farms](https://www.amazon.com/FoxFarm-Forest-Potting-Outdoor-Fertilizer/dp/B08W2CB7GV/ref=asc_df_B08W2CB7GV?mcid=ffbf70e51b11367693b5022c10e0bb26&tag=hyprod-20&linkCode=df0&hvadid=693713553301&hvpos=&hvnetw=g&hvrand=1684627692628527747&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9002004&hvtargid=pla-1948805306562&psc=1) that my fungus gnat problem drastically improved. I have literally no other reason aside from my anecdotal evidence to back it up but it may be worth a shot.
I have applied that diatomaceous earth to all my plants with lots of exposed soil. It helps with all sorts of pests and I had aphids on some plants and it seemed to help as did neem oil spray.
Less water
Those UV light sticky traps. Cheap knockoffs are on Amazon and work the same. Can’t live without them.
I let my plants (all plants) dry out for about two weeks and then watered with peroxide water once and then repeated this process for several weeks. I also placed the yellow traps pretty much as a blanket across the soil in nearly every pot. I bleached every drain in my house. I was finally able to conquer those annoying flying buggers.
Sprinkle ground cinnamon on the soil.
Neem Oil has always done right by me.
In my country gnatrol is unavailable, and i havent found any mosquito bits with BTI as well, and I havent tried nematodes as well.
What I tried are neem oil, letting it dey out, spraying with isopropyl alcohol and hydrogen peroxide, none worked, they only managed the populations.
Slowly I thrown out every pot of soil where ive seen them fly out of, and put the plant into leca/perlite/water, but even just a few adult survivor could repopulate in the remaining soil plants.
When I was about to lose my mind in anger, I spent a day throwing out EVERY remaining soil except one ( i covered the top of the pot with sticky traps)
So far I may have seen one or two remaining adults, but as they have no place left to lay eggs, and semi hydro is easy to flush out, I think they’re may be gone for good.
My solution is a bit drastic and tiring (even when I did it in 5-6 parts) for my 80+ plants, but they’re finally gone😭😭😭
Bonide systemic granules mixed into the top of the soil of each plant. BOOM gone.
Tried it all…. Only thing that worked was soda water from soda stream
Keep the first few centimeters of the soil dry, powdered eggshells will help kill the larvae, keep all the plant matter (leaves) from touching the soil.
Water with mosquito bits tea (every time), eventually they’ll die. Also suggest getting carnivorous plants. Imo The easiest to take care of are pinguiculas.
Sprinkle diatomaceous earth (I got mine at Tractor Supply and it should be available at garden centers) on top of the soil. As the fungus gnat larva try to emerge, they will tear themselves apart in the diatomaceous earth particles.
Works for me!
Need oil
*neem oil
pour hydrogen peroxide on the soil
A layer of sand worked for me. Just enough to cover the soil, not too deep. For the remaining bastards flying around, Zevo sticky night light traps did the rest.
Systemic works for me.
Buy some carnivorous plants
, I have many easy to care ones for sale including ones that act like fly paper to kill adults and others that kill the larvael stages of the fungus gnats. DM me if interested , after getting into carnivorous plants fungus gnats have never been an issue anymore and I have hundreds of plants. Use nature to fight nature . Sticky paper is just a bandaid
Water from the bottom and keep the top dry. Or just get some BTI like mosquito dunks
I mix mosquito bits into my soil when I make my mixes. Im down to almost zero frickin gnats.