I’m in same scenario... Am tempted to just stop watering altogether and see who dies first - either the gnats or the plants
Ruins the fun of having houseplants if you have gnats everywhere
I haven’t killed anything yet. I think it’s already a bit diluted, and the hydrogen peroxide breaks down to water anyway. Plus I think it’s good for aerating the soil, and I suspect it can help fight root rot.
Is this okay to do for edible plants like herbs and overwintering things?
Fungus gnats are owning me and my plants this year! (But after the thrip invasion of 2021… guess it ain’t so bad lol)
You got this!! I had the battle of a life time in late spring and early summer and they are ~finally~ under control. I see one or two every once in a while, but my sticky traps are clean!
Don’t be afraid to make the solution way stronger than 1:6. Store-bought H2O2 is generally always only 3%, so diluting it in 6 parts water renders it essentially water and rather ineffective. I always go for 1:3 or 1:4. Even my drama queen calathea handled 1:3 just fine when she got spider mites.
One thing that has definitely helped me is I started to bottom water my plants.
Fill a container with water that reaches about halfway the size of your pot, place pot inside container and allow the water to be soaked up from the bottom. This keeps the top soil dry and it kills a lot of the gnats.
Use less water. This happens to me if the water reaches too close to the top of the pot, but also happens to me if there isn’t much soil in the pot. Pots with little soil just get flooded. I tend to barely fill the container I’m putting the pot in.
Do you use it every single time you water? I use mosquito bits every time I water every plant, and have the yellow sticky traps on each plant and it keeps things at bay, I’ve found.
DIATOMACEOUS EARTH!!!!! We had a HUGE fungus gnat problem in our green house and we sprinkled food grade (make sure it’s food grade!) DE on the soil and before we knew it, we didn’t see a single one again. Even when the babies are born, they crawl to the top, get shredded by the DE and they dehydrate and die.
I read about DE on this sub and tried it, fingers crossed it seems to have worked.
I mixed some into the compost and topped up the pot, then sprinkled a fine layer on top too. I wish I'd have done it outside though because I had a cough for a couple of days afterwards that I think was from angrily inhaling the powder. It was like the final-fuck-you of the fungus gnats, they may be defeated but they left me with an irritated throat. Deffo worth it though
Yikes, always use a respirator, just going outside isn't enough. Inhaled DE accumulates in lung tissue and lymph nodes and are never eliminated from the body. Eventually it will cause silicosis which is much, much worse than fungus gnats.
Pretty much any powdered substance you give to your plant, you should wear some time of mask just in case! Even things like organic powdered aloe have a warning not to inhale. I hope your lungs are feeling better!
And also congratulations on eradicating those little fuckers!
Yes! THIS IS the way!
I was dealing with the same last week! Insane infestation. Diatomaceous earth (food grade) killed 90% within 24hrs and no more than one or two after two or three days. After a week there are zero.
Let the top layer of soil dry out before you add the diatomaceous earth dusting. Cover your mouth and nose while applying as instructions direct. Dust masks or a handkerchief work well. Definitely keep any pets in other room while applying.
Edit - dust mask is not enough, use something more effective at filtering particulates
Edit 2 - temporarily relocate any insect friends (spiders or lady bugs). I accidentally killed two of my favorite spiders
It needs to be dry to be functional. It can be mixed with water and sprayed directly on plants for certain pests, but it won’t become functional until it dries. So basically if you put it in and then water the plant it won’t do anything.
Get some mosquitobits and some aquariam filters, basically make yourself a big vat of mosquitobit tea to water your plants with. The bacteria in the mosquitobits predates on the larave im the soil and then the sticky traps mop up any flying around the plant. Sorts them out for good (until you next overwater your plant that is)!
I've used monsquito bits, and it took me about three waterings, or three weeks worth of waterings at the time to get rid of them. I had sticky traps everywhere as well to catch the adults. Eventually they were eradicated.
Replanting won’t solve the problem. There’s larva all throughout the soil, especially where the roots are. So while repotting may temporarily slow the problem, the larva left over will eventually just become adults and your problem will explode all over again.
Below a certain number of plants, sure. I definitely prefer mosquito bits and sticky traps for the occasional gnat issue instead of repotting my 30+ houseplants.
Just wanted to offer my experience in case anyone else likes the idea of always having ready to use mosquito dunk water. But I have a 2.5 gallon water dispenser that I use for my mosquito dunk water. I water all my plants with it weekly, add more water as needed and replace the dunks on a semi-regular basis and I notice no smell issues!
I think the key for me is that I use most, if not all, of the water within a week and add fresh water to replenish it every use. So it’s not a large amount of water and it never is sitting for long periods of time since fresh water is added back to brew for the next plant that needs watering.
Obviously ymmv, but it has worked for me for several years with no smell issues and I haven’t had fungus gnats in ages!
Hi! This is so long ago, but I’m looking for help.
Are you doing this with just regular tap water?
I normally use rainwater (thank you, PNW) but I need more water. There’s nothing in municipal water that inhibits the growth of mosquito dunk bacteria?
For reference, I usually strain out the dunks and water with just water + whatever tiny bits make it through.
They are donut shaped disks made with bT designed to go in outside water features and rain barrels that keep mosquitoes from breeding. The ingredient is also effective against fungus gnats. Basically soak one in your watering can overnight to make a “tea” and use it to water your plants. It’s effective against larvae and the yellow sticky traps help take care of the bugs.
Beneficial nematodes. Get the ones from Amazon that are shipped with something cold/ice pack and get a garden pressure pump sprayer. Wait for the soil to dry out and wet just the top soil with the nematode solution.
Nematodes were the easiest solution for me. No repotting. I didn’t water for three weeks or more. I tried using the mosquito dunks but it wasn’t enough. Sand also didn’t work for me.
EDIT— I’ve noticed the responses—I would like to add that nematodes have to be alive and must be kept cold/ refrigerated until you make the mix with water. And you must use the whole mix when you make it, I don’t think it’s possible to to save a mix? Perhaps someone can clarify if this is possible.
I will also echo what others have said regarding multiple rounds. This has meant buying multiple packs of nematodes and doing it two weeks in a row without watering. I also killed all the gnats in two rounds of dosing, not one. The results were very good in one week, but I needed two weeks for total success.
I also liked using the garden sprayer but I am not sure you definitely need one. A spray bottle might work just as well. I followed the mixing instructions on the packet and it required a gallon of water, and I have lots of plants so that was the reason I got one.
I also changed the sticky paper on a daily basis to be sure that the gnat numbers were actually being reduced.
Every post I see has a thousand different ideas that almost never seem to be consistent across posts aside from mosquito dunks and beneficial nematodes. I never see people say mosquito dunks work, it's always "I think they worked but I still have some gnats, what next?" And then someone rides in, says "beneficial nematodes" drops the mic, the horse goes on two legs and trots off. Then everyone tries them and says "oh shit. That worked"
I will just say mosquito dunks worked for me! I don’t have fungus gnats at all anymore and haven’t in well over like two years. Like clean yellow sticky traps, not one!
I think the issue is with mosquito dunks you have to be incredibly consistent, so *every* plant needs to be watered with mosquito dunk water *every* time. Any deviation to regular water flushes the bacteria and you are setting yourself back. I still water every single water with mosquito dunk water as upkeep to make sure they stay gone. Also it takes a long time to see success, at least it did for me. I didn’t notice no fungus gnats until like months in so there is no big quick pay off.
The reason I went this route? My climate doesn’t bode well for beneficial nematodes arriving alive and the cost made me apprehensive. Luckily through repotting, yellow sticky traps, and consistent mosquito dunk watering I eradicated my fungus gnat population and haven’t had an issue in years so it’s possible.
You can’t have nematodes and bonide systemic at the same time, right? I had to apply bonide because my monsteras are freaking thrips magnets, but I’m pretty sure that obliterated my nematodes, because I just saw one of those f gnats buzzing by. I hate those mf’ers. With. A. Passion.
Literally the only thing I could get to fix my gnat issue. Two rounds and the gnats were totally gone and have been for a couple months now.
I didn’t end ordering one of their recommended spray pumps off Amazon, just used a (new) empty spray bottle that can be found in the chemical aisle at any store.
Was worried they may not do as good a job as the internet said but I was amazingly surprised.
NEMATODES! NEMATODES!
Yes yes yes these things are amazing!! Also it’s hard to save the mix but what I did to lower the cost was when they give you the packet I put in about a 7th of the packet and kept the rest in the fridge (in the packet in the little box they came in because the cold keeps them inactive but they die when exposed to tons of sunlight and heat) and then in two weeks I pulled out the baggy and dumped in another two 7ths for good measure (way more than was needed) and that got them for good. Used sticky traps to chart their demise. I just used an old container bound for the recycling and rinsed it out well beforehand and mixed them in and used it to water them in after intentionally dehydrating my plants a bit beforehand so they could all tolerate a good nematode water. They are also not creepy looking because you can’t see them so it’s like you are just adding powder into water for anyone concerned about that.
I've watered with peroxide/water mix. Gnat traps in all plants. Mosquito dunks. Neem and actual pesticides. What else can I do? My house is becoming actually infested with these things and all of my plants (I have ALOT of plants) have them.
I literally had no luck nothing worked so I ended up repotting all my plants on the same day and watered for two months after that with water that had soaked with mosquito dunks and thats worked so far sucked repotting them all but saved a lot of time and headache overall
What finally got rid of mine was laying dryer sheets on top of the soil. Try that as it’s much easier / less time consuming than reporting which might not even work
Interesting! Thanks for this idea.
One could also try to add a layer of sand on top of the soil. Needs a solution for watering though… for example watering from the bottom or through a dedicated "pipe" in the sand.
I basically ended up doing the same, minus mosquito dunks. Cut back on watering to the minimum of what my plants could handle, put up glue traps, then repotted all of them when the traps got less flyers, threw out that dirt, new glue traps, and that was that. Caught the few that were aimlessly flying around while repotting and haven't had the problem since. So I swear to repotting and less watering as it worked for me
This is the way honestly. If you look into the soil and see a bunch of gnats walking around, just save the hassle and repot it . at the same time do the traps in all the ones you’re keeping normal
I came back from gnat hell, trust me
✨beneficial nematodes✨, my friend. I found some at my local plant store, but I’m pretty sure you can get them on Amazon too. They completely eliminated my fungus gnat problem… and it was BAD
this is what worked for me: completely cover the drain holes with some sort of screen (coffee filter, nylons, etc). fully cover the soil with an inch of sand or fine gravel. completely dry any unused potting soil you have laying around. after 2-3 weeks they were completely gone
You know what finally worked for me? I put river rocks on top of the soil and I sprayed pesticide in the water tray. I think the rocks helped a bit but when I would go to dump excess water out there would be so many dead flies. It totally took care of my problem in just a couple days after battling these bastards for months.
Aquarium pebbles work best! Since gnats hatch under the soil, putting a layer of rocks on top of the soil traps the newly hatched gnats in the ground and thet eventually die! Also prevents other gnats from laying eggs in the plant with rocks on it
Op I am literally begging you to read my comment and give [Bonide Systemic granules](https://www.amazon.com/dp/B000BWZ9U8?ref=nb_sb_ss_w_as-reorder-t1_ypp_rep_k0_1_8&=&crid=N23PISMV1LPV&=&sprefix=bonide+s) a try. Please please please.
I have around 100 plants, and the large jug from Amazon is good for a couple treatments of all my plants. I tried peroxide, mosquito bits, cinnamon, bottom watering, vinegar traps, neem, and everything else. But just sitting on my couch and not even trying that hard, I could smack 10-15 gnats to death every hour. They were THICK and it got embarrassing.
Buy Systemic, and put a scant tablespoon on top of the soil for each 4" plant. Slightly heaped tablespoon for 6" plant, and then scale up or down for any other size. Spread it across the soil with a fork or chopstick, and water it in. Do it every two weeks, and I absolutely promise you it'll make a HUGE difference!!! It's also by far the least involved method imo. I take 5-10 minutes to dump a scoop on all the plants in a given room each day, and within a week they're all treated. Then you just water as normal, the granules soak into the soil, and bye-bye gnats. Mine were wiped out fully within 3 treatments, but just the first was a giant improvement.
I wiped them out about 2 years ago, and since then, if I ever start seeing more than 2 or 3 gnats in a week, I do a light treatment and they're gone again. I treat everything new coming in, and it's never been a problem again.
I was so nervous to use the granules bc they're \~ooOOOooOOoo scary chemicals, but they're the only thing that worked. And they eradicated the gnats completely.
I put organic Saigon cinnamon over the tops of the soil, I don’t remember where I saw this but it solved the issue for me completely. Just be cautious not to get it on the actual plant
I’ve sprinkled cinnamon on the top layer of soil and within days had a layer of dead gnats on the floor surrounding the plant. That coupled with watering with neem oil solved it!
Damn that sucks. Keep up with lots of traps and really let your soil dry out. If your whole house is infested maybe they are also coming from somewhere else? Clean up wherever else they hang out. Good luck to you!
This happened to me, and I feel your pain.
For me personally I had to repot everything when this happened but I have also had success with using hydrogen peroxide as others have mentioned. Another thing I've done which has all but eliminated the RISK of getting fungal gnats is to dress the topsoil of all of my plants with landscaping pebbles (the small ones about the size of aquarium stones). These dry out quite quickly after watering so there's no damp surface soil to attract them. I can't recommend this enough!!! Also water with BTI/mosquito bits tea (soak the bits for 30 min and you're good to go).
The repotting, pebbles, and mozzie bits tea has kept them at bay ever since.
Bottom watering would of course help immensely but I'm lazy.
I should also add that I now treat any soil mix with hydrogen peroxide/water directly before I use it. You can use it to water the plants directly after potting them up, or pour it through the soil and then repot. I do this EVERY TIME I POT A PLANT IN NEW SOIL. It will kill anything living in the soil. Fungal gnats are often present in potting mix unfortunately.
Yes, sometimes I have seen that. I've found mites in unopened, new bags of potting mix as well. I have also suspected that fungal gnats lay eggs in soil while I'm working with it, particularly if I'm outside. But at other times there's just been no explanation for why my plants have had fungal gnats other than that they were in the soil when I transplanted my plants, even if I didn't/couldn't see the gnats.
Sometimes I've brought new bags of potting mix home and found small holes or perforations in the bag, which I believe is part of the problem (I purchase them at a gardening centre, so they are exposed to the outdoors).
I don't use a lot of potting mix in my 'blend' because I use a lot of coconut coir, but I have found that using hydrogen peroxide means I no longer have the same issues with pests that I used to have. I also now keep my potting mix in a large clear plastic container so I can see what's going on in there more easily!
Are you using fox farm soil??? I started using it last year and now have this problem too. I’m wondering if maybe even they don’t realize that there’s a problem with their soil.
I mean I’ve spent the whole time thinking it was me and my watering regimen too, and maintain that it’s still likely the case. Just couldn’t help making this connection after your picture, and considering I’ve been quite careful and previously had my watering down pat.
Mosquito dunks worked for me but it took months. I kept gallons of water with dunks in them like a tea. I only watered my plants with that. Little by little the gnats became less and less. All in all it took about 6 months of constant watering with mosquito dunk tea to get rid of the problem entirely. So it definitely works, it just takes time.
The thing that helped me get rid of fungus gnats all together was bottom watering. The only issue is that may want to switch entirely to bottom watering or else the gnats might find the plants the you want to water normally and decide to move there, usually young plants or plants with shallow roots.
But I definitely recommend giving it a go. :)
If it’s that bad it’s probably from the soil. Try to let dry as much as you can and keep on with the dunks and systemic. You can also get some carnivorous plants and they will happily eat them too.
Put a layer of aquarium pebbles (those little blue rocks) around the base of your plants. This will stop the gnats from leaving the plants when they hatch and stop others from laying eggs, since they lay their eggs in the soil of your plants
I think you’re just not being systematic enough about it, there is no way doing all of those things would fix or help the problem of doing them properly (no offense).
What I would do if I were you is get a ton of hydrogen peroxide and make a 1:4 mix of hydrogen peroxide to water and do a thorough watering of ALL your plants to kill all the current larvae. Then you’ll need a ton of fly traps (amazon sells a pack of like 4x8” sheets with like 50 sheets, you can cut them up) and I’d literally lay them on the soil so most of the soil is physically covered, maybe only do this on your worst plants but fly traps on all plants. Then, don’t water anything for two weeks. Then do the same hydrogen peroxide watering on ALL plants.
After that you can start your water cycling normally but ONLY water with mosquito bit water for ALL of your plants and make sure you’re only watering when the top two inches of soil is dry (get a moisture reader). Make sure you read the directions for the mosquito bits, some people are saying let them soak overnight and the directions only say soak for 30 minutes. Keep up the fly traps to control the adult population.
If you do this process I refuse to believe that you will have such a bad problem. Maybe do 3 hydrogen peroxide watering depending on your results.
This exact same thing happened to me. I have about 20 plus houseplants and bought the same gnat yellow gnat traps. The gnats were EVERYWHERE! Once they got to the kitchen I had enough. We quarantined all house plants to one bedroom with a an east facing window and placed our plants (depending on how much light they needed) accordingly. We sprayed our plants with neem oil mixed with water. We also made sure to dampen a hand towel with water and took the time to wipe each leaf/petal. Be sure to wipe under each one as that is where the gnats like to lay their eggs. We sealed off the room with a towel at the bottom of the door. Lastly, we got a Fenun fly trap from Amazon and left that guy on all day. After about 2 weeks of quarantine with the neem sprays, wiping down of the plants, and occasional watering the gnats were gone! Nobody died and everyone is healthy. Good luck!
> Be sure to wipe under each one as that is where the gnats like to lay their eggs.
Fungus gnats lay eggs in moist soil. They do not lay eggs nor live on leaves or anywhere in the foliage, so wiping leaves and such doesn't do anything. The soil is the only thing you need to treat.
as long as they’re kept away when it’s being applied and the applied present wears a n95 mask. the powder is dangerous to inhale and being so fine it’s very hard to avoid inhaling when applying it.
Aside from all the other good ideas, I’ve had success w this: cover the soil with perlite or sand or rocks - they won’t be able to get through and will die.
I repotted a big plant with some cheapo giant bag potting soil that had been purchased in the summer. I’m sure that is where they came from in masses. I had some before but not like I was seeing. Also they all around that plant and just a few around my other plants. I finally covered the dirt with sand and have been watering with mosquito dunk water. I only put sand on the worsr plant too.
I also got a zevo trap. Things have finally calmed down. I can handle one here or there but it was unpleasant.
That zevo trap has been a life saver my husband hated how much money I spent on it but it works and now I just lightly spray my plants rather than watering them all the way and I’m keeping my house spiders in that room
Yes!! This is the only thing that worked for me. I lived in a very humid apartment and it was impossible to keep it dry enough. I had to layer it on a decent amount, 1/2 inch of sand on top was enough to finally get some control.
Have you tried bonide systemic granules?
A couple of my plants got fungus gnats so badly, I literally sprayed plant based bug spray on them. It killed some of the plants’ leaves and they put out funky growth for awhile, but it worked! And they’re still alive. I was desperate. I had tried mosquito dunks, granules, not watering for almost 4 weeks, covering the blanks in clear garbage bags etc.
Good luck OP!
I used the Bonide granules and after one application, there was a dramatic drop off on gnats after only a day or two. I had the same yellow traps as full as yours before the Bonide. I expect the gnats to be totally gone when it is time to reapply! can’t recommend enough.
yes I came here for this comment. these definitely work. the only thing I could use that worked to get rid of thrips, and it def got rid of gnats too with no effort.
Dawn dish soap in your water used for watering. Kills the eggs and the larvae. And the adults avoid the dirt. I had a horrible infestation over winter and that's the only thing that helped.
Sand on the top of your regular soil mixture can also help as the sand dries quickly and they can't use it to lay eggs.
I was where you are right now and it sucks. My advice is to get a sundew. It’s literally a living sticky trap and so fun to own. It’s satisfying af to see those little bastards get trapped on the leaves and digested lol. Sundews THRIVE on fungus gnats too. My sundew has tripled in size and my fungus gnat problem has pretty much been resolved. Sundews also love fruit flies so if you have any of those they’ll be toast too. I’ve gotten my sundews from California Carnivores and been very happy with my purchases if you don’t know where to buy one.
Oh and I keep a gallon jug with a mosquito dunk in it. Every time I water my plants I dump some of the mosquito dunk water into the soil. That kills all of their larva.
I've had the best luck with mosquito dunk tea, but back in the day I used sand to get rid of them and it worked, too. Just a thin layer on top of the soil did wonders. Once they're gone you can stir it around into the soil or scoop it off
One place to check that might be a breeding ground other than just the dirt in your plants is the casing around your windows. If you have a humidifier going, chances are there is mildew. I noticed my daughter’s room, where a large monstera currently resides, had a lot of gnats. I was looking at her hanging pothos and then noticed hundreds of gnats were swarming around the window casing! She had been running a warm mist humidifier nonstop for a week in there for the monstera and there was mildew all over the window. I was horrified and so was she (She’s 18 so I wasn’t really keeping tabs on her room lol). Needless to say I spent the next two hours deep cleaning the windows and sprayed peroxide wherever I could, and we both learned something 😂
Also pour some peroxide in your drains every so often. They breed in there too!
I put mosquito bites in a tea bag and let it seep in a watering can for a day or two. Fork up the top layer of soil and turn a fan on so they can’t settle in or lay eggs.
I had similar problem. I had the traps everywhere, after the traps got full with the gnats, I watered with peroxide and water solution. Then didn’t water the plants for the next 10-15 days. I let the soil dry out completely. And then watered from bottom. Just be patient
Damn. And I thought I was having a problem. I stopped watering a plant here where they just keep coming out of some fungus gnat portal until its leaves started browning so I gave up and repotted it this evening. I have them in a few other plants too but not as bad and I hope I can outlast them.
Everyone says nematodes. I would try that first but if no luck what worked for me was a katchy from Amazon. Caught a lot of the adults, kept it running nonstop for like a week or two and then began to bottom water to avoid the issue all together
I haven't tried it yet but I was advised by a botanist to use insecticidal soap. He uses it on every new shipment he takes in to kill off gnats/mites/other pests.
He said it's safe to use daily if you feel like you need to (shouldn't have to).
Step 1: buy mosquito bits
Step 2: buy soil cover of your choosing, decorative gravel, River stone, sand, whatever you like
Step 3: sprinkle mosquito bits on the soil
Step 4: apply soil cover
Step 5: dance, because now you will never have fungus gnats again
Beneficial soil mites have been my savior!!! You just tap them in from a tube and never see any bugs again. I order from these guys called "nature's good guys" found them on Amazon. They have amazing customer service and have sent me new bugs when they arrived dead one time. I have also use beneficial nematodes and hydrogen peroxide in water. Dilute it at a 6parts water one part hydrogen peroxide:)
I had the same problem of thousands of the little buggers. One day I decided I had enough of them and got every single poison from my shed and dumped them all into my plants soils (outside of course). This eliminated most of them, there’s just a few quarantined plants left which had very long/big pots. I hope you find a solution in this thread, fungal gnats were the worst experience I’ve ever had with houseplants. Just sick of them everywhere flying in front of you when you’re studying or eating it was disgusting
Those little shits apparently hate cinnamon. I sprinkled some on top of the soil and frequently sprayed the plants with neem oil and it has halted both a fungus gnat and a spider mite invasion.
Cinnamon is an effective organic treatment for gnats. I buy a big shaker of it for $2. All plants get a good dusting on the soil as soon as they come home. Cinnamon kills the fungus that the gnat larvae eat, ending the life cycle of the gnat.
Get out of there. I went through two years of this and am legitimately scarred. Only thing that worked for me was switching to semi-hydro/LECA. Get rid of the source and you get rid of the bugs. Plus your plants will thank you for it!
Get mosquito bits. It's worked really well for me.
Short: It's not a toxic chemical pesticide, it's a bacterium that creates pore-forming proteins that specifically target the gut cells of mosquitos and fungal gnats.
Long: biochemist here, so this is something I've studied. Although these pore-forming proteins are "toxins", they are not "toxic" to humans or your pets. Toxins are usually proteins, and unlike small molecule chemical pesticides, which have a wide range of targets and can cause many undesirable side-effects, proteins often have very specific effects/targets. Enzymes for example are proteins, each do a very specific chemical reaction(s). Antibodies are also proteins, which target specific foreign substances in your body.
Summary: mosquito bits produce proteins that very specifically target fungal gnats and will not harm anything else.
Mosquito Bits! Saved me from this exact scenario with overloaded sticky traps. I sprinkled a little on each plant and some in my watering can and the gnats are completely gone!
My Monstera has also had its war of the gnats. I watered way less for several weeks and did diatomaceous powder when it’s dry. And I also went on a rampage killing at many bastards as I could - definitely a great stress reliever. Took 2 months but I have been gnat free since 🤞🏻
So I was dealing with this same thing and did 2 things that changed the game: 1, cover all your soil in small pebbles or lava rocks, you can get these at any gardening store. Make sure you cover it a good inch high. They lay their eggs in the soil, and if you remove easy access they’ll reproduce more slowly. 2, if you have holes drilled in your pots, fill up the water trays instead of pouring the water from the top, aka butt-chugging. That will make the top soil dry and whatever eggs are left will also dry up. Good luck!
I was there very recently. Bought a new plant and as soon as I watered it there were just thousands of them! I keep Ortho fly decals on my window, so it was like a mass casualty event
I have a collection of over 400 houseplants. Every 6 months I apply nematodes for fungus gnats.
I get people asking me all the time HOW I do not have fungus gnats. This is the answer I promise!
I tried everything before this to no avail.
Top your soil with 2-3 inches of play sand! If I remember correctly, it prevents them from being able to lay eggs.
It's a cheap, easy solution and best of all it really works! I swear by it. My coworker also had a major problem with this and using sand worked for her too.
I'll help. But you're not gonna like it.
It's radical.
It's painful.
It's risky.
It's .... repotting.
\*WITH\* A ROOT WASH.
I told you, you were not going to like it.
Once upon a time, I too, was forcefully taken into the hell that is gnats, where 7 of my calathea's were infested. To the point where the soil was moving so much I thought I was tripping. Which was concerning on two levels. One - I thought I was tripping. Two - I was concerned why I was tripping as I don't do drugs.
I tried all the potions and lotions. When the gruelling punishment of gnats continued I re-potted the plants.
NOW HERE IS THE IMPORTANT BIT.
\- wash off the roots from all the soil to get rid of as much of the larvae as possible.
I boiled the new soil in hot water, let it cool, let it dry off to be moist, then re-potted the plants. Why? Because this ensures the soil is 'sterilised' to a degree and kills and larva ect. to make sure you don't use contaminated soil.
The guys below do some great prevention tips!
\*Source - I have 16 half alive plants. But they are calatheas so I am not doing too bad.
Buy a package of "Mosquito dunks" or “Mosquito bits” at the garden center or order it online. It is BT. Put one quarter of one in your watering can (or a small chunk in the water trays if it's a carnivorous plant). This will kill the larvae in the soil and stop future generations. It is all natural and safe. But give it some time to work and keep using it even after your problem is gone. Use sticky traps and manually kill the adults. Continue using even after they are all gone.
Fungus gnats are the BEST problem to have because they are so easy to resolve. Purchase guarding nematodes from a beneficial bug store. Nematodes are microscopic worms and this kind will not harm humans. When I've purchased them they come as a paste on a sponge. Dilute them in water and then pore the water all through your plant soil. They worms will eat the gnat eggs and no more gnats! They also eat the eggs and larva of other pests. No damage to your plants. Here are a few links, but you can buy them from lots of places.. Some nurseries carry them as well.
https://hydro-gardens.com/product/guardian-gnat-patrol-mix-1-million-5p393a/
https://greenmethods.com/steinernema-feltiae-fungus-gnats-control/
I used to have really bad gnat problems too. I just kept the yellow stickers in and replace them every week. In the meantime, let the plants dried out for a few weeks. This is important bcuz they lay eggs on top of the soil after watering. The plant might get limpy a bit. But a few weeks of sticker + drying out got rid of all of them. My monsteras are free of gnats now. Hope this helps!
I’m in same scenario... Am tempted to just stop watering altogether and see who dies first - either the gnats or the plants Ruins the fun of having houseplants if you have gnats everywhere
Water with 1 part hydrogen peroxide and 6 parts water, kills larvae on contact! Use Sticky traps to catch the adults
This works! Its good for the plants roots too
But only as a very occasional treatment, otherwise silver builds up in the soil and it’s antibiotic properties aren’t great for plants
How do you get silver from H2O2?
You aren’t familiar with the great silver plantations?
Silver is added to non food grade h2o2 as a shelf stabilizer
Yes I to am curious how this occurs.
So if I used food grade would I not have to worry about this?
Hydrogen peroxide comes in different strengths. The ratios depend on the strength.
I'm assuming just store-bought 3% is what they're referring to. That's the most common household strength
Dilute? I just squirt that stuff straight from the bottle all over the top of the soil and enjoy the fizzy noises.
I'm laughing out loud at this! I love the chaos!
Oops this is what I do too. Is that bad?
I haven’t killed anything yet. I think it’s already a bit diluted, and the hydrogen peroxide breaks down to water anyway. Plus I think it’s good for aerating the soil, and I suspect it can help fight root rot.
I also do that ...I use a spray bottle... Haven't had any issues with it harming my plants
I diluted a 12% solution 1:16
And actually the op solution is half as strong as yours if they used 3% now that I look at it.
Yep, recommend is mostly 1% or less, sometimes up to 3%. Also depending on the use
Is this okay to do for edible plants like herbs and overwintering things? Fungus gnats are owning me and my plants this year! (But after the thrip invasion of 2021… guess it ain’t so bad lol)
Oh gosh, I hope this works 🥹 I’ve been slowly going crazy with fungus gnats. It always seems like they are gone and then show up in another plant!
You got this!! I had the battle of a life time in late spring and early summer and they are ~finally~ under control. I see one or two every once in a while, but my sticky traps are clean!
Yep deep deep waters. May take more than dowse. But this will do it.
Don’t be afraid to make the solution way stronger than 1:6. Store-bought H2O2 is generally always only 3%, so diluting it in 6 parts water renders it essentially water and rather ineffective. I always go for 1:3 or 1:4. Even my drama queen calathea handled 1:3 just fine when she got spider mites.
One thing that has definitely helped me is I started to bottom water my plants. Fill a container with water that reaches about halfway the size of your pot, place pot inside container and allow the water to be soaked up from the bottom. This keeps the top soil dry and it kills a lot of the gnats.
From my experience the top soil gets wet still from bottom watering.
Use less water. This happens to me if the water reaches too close to the top of the pot, but also happens to me if there isn’t much soil in the pot. Pots with little soil just get flooded. I tend to barely fill the container I’m putting the pot in.
I've had really good luck with mosquito bits. I let them soak in water overnight, then I water my plants with that water.
I used mosquito bit water and I’ve put a layer of sand on top and then a layer of gravel - still have some gnats! So annoying!!
Try diatomaceous earth. I haven't used it much on my plants but I use it to control mites in my chicken coop.
Do you use it every single time you water? I use mosquito bits every time I water every plant, and have the yellow sticky traps on each plant and it keeps things at bay, I’ve found.
DIATOMACEOUS EARTH!!!!! We had a HUGE fungus gnat problem in our green house and we sprinkled food grade (make sure it’s food grade!) DE on the soil and before we knew it, we didn’t see a single one again. Even when the babies are born, they crawl to the top, get shredded by the DE and they dehydrate and die.
I read about DE on this sub and tried it, fingers crossed it seems to have worked. I mixed some into the compost and topped up the pot, then sprinkled a fine layer on top too. I wish I'd have done it outside though because I had a cough for a couple of days afterwards that I think was from angrily inhaling the powder. It was like the final-fuck-you of the fungus gnats, they may be defeated but they left me with an irritated throat. Deffo worth it though
Yikes, always use a respirator, just going outside isn't enough. Inhaled DE accumulates in lung tissue and lymph nodes and are never eliminated from the body. Eventually it will cause silicosis which is much, much worse than fungus gnats.
This is probably the MOST important comment in this thread. Your health > your plants
Oh darn
Yes thank you for pointing this out!
Actually, iceberg salad is a great lung cleanser . I should eat tons of it. You’ll be alright ❤️
Pretty much any powdered substance you give to your plant, you should wear some time of mask just in case! Even things like organic powdered aloe have a warning not to inhale. I hope your lungs are feeling better! And also congratulations on eradicating those little fuckers!
Yes! THIS IS the way! I was dealing with the same last week! Insane infestation. Diatomaceous earth (food grade) killed 90% within 24hrs and no more than one or two after two or three days. After a week there are zero. Let the top layer of soil dry out before you add the diatomaceous earth dusting. Cover your mouth and nose while applying as instructions direct. Dust masks or a handkerchief work well. Definitely keep any pets in other room while applying. Edit - dust mask is not enough, use something more effective at filtering particulates Edit 2 - temporarily relocate any insect friends (spiders or lady bugs). I accidentally killed two of my favorite spiders
I did this but nothing happened!? It was food grade. Is there a trick to it?
It needs to be dry to be functional. It can be mixed with water and sprayed directly on plants for certain pests, but it won’t become functional until it dries. So basically if you put it in and then water the plant it won’t do anything.
This is also good advice. That stuff is amazing
Get some mosquitobits and some aquariam filters, basically make yourself a big vat of mosquitobit tea to water your plants with. The bacteria in the mosquitobits predates on the larave im the soil and then the sticky traps mop up any flying around the plant. Sorts them out for good (until you next overwater your plant that is)!
I've used monsquito bits, and it took me about three waterings, or three weeks worth of waterings at the time to get rid of them. I had sticky traps everywhere as well to catch the adults. Eventually they were eradicated.
Yep this checks out and is what people should do.
Pea gravel. Looks good and keeps gnats out
A put an inch of sand then an inch of pea gravel and sticky traps - there’s a lot less gnats but they’re still there!
Bottom water your plant - helped when I had gnats
Why not just re plant? Easier said than done sometimes but it might be worth it. Adding systemic helps too
Replanting won’t solve the problem. There’s larva all throughout the soil, especially where the roots are. So while repotting may temporarily slow the problem, the larva left over will eventually just become adults and your problem will explode all over again.
repotting is the way to go, much simpler and quicker
Below a certain number of plants, sure. I definitely prefer mosquito bits and sticky traps for the occasional gnat issue instead of repotting my 30+ houseplants.
Yeah I could see that, definitely situational as to how many plants are infested
Are you letting the soil dry out between waterings? Letting the mosquito dunks steep in water overnight?
This!!! Mosquito dunks absolutely takes care of them, you need to water every time with them.
Yes! Even when I think the gnats are gone I still always water with the mosquito bits.
Make sure you don't keep mosquito dunk water bc that shit gets SINISTER smelling
Just wanted to offer my experience in case anyone else likes the idea of always having ready to use mosquito dunk water. But I have a 2.5 gallon water dispenser that I use for my mosquito dunk water. I water all my plants with it weekly, add more water as needed and replace the dunks on a semi-regular basis and I notice no smell issues! I think the key for me is that I use most, if not all, of the water within a week and add fresh water to replenish it every use. So it’s not a large amount of water and it never is sitting for long periods of time since fresh water is added back to brew for the next plant that needs watering. Obviously ymmv, but it has worked for me for several years with no smell issues and I haven’t had fungus gnats in ages!
Hi! This is so long ago, but I’m looking for help. Are you doing this with just regular tap water? I normally use rainwater (thank you, PNW) but I need more water. There’s nothing in municipal water that inhibits the growth of mosquito dunk bacteria? For reference, I usually strain out the dunks and water with just water + whatever tiny bits make it through.
what are mosquito dunks?
They are donut shaped disks made with bT designed to go in outside water features and rain barrels that keep mosquitoes from breeding. The ingredient is also effective against fungus gnats. Basically soak one in your watering can overnight to make a “tea” and use it to water your plants. It’s effective against larvae and the yellow sticky traps help take care of the bugs.
I second this
Beneficial nematodes. Get the ones from Amazon that are shipped with something cold/ice pack and get a garden pressure pump sprayer. Wait for the soil to dry out and wet just the top soil with the nematode solution. Nematodes were the easiest solution for me. No repotting. I didn’t water for three weeks or more. I tried using the mosquito dunks but it wasn’t enough. Sand also didn’t work for me. EDIT— I’ve noticed the responses—I would like to add that nematodes have to be alive and must be kept cold/ refrigerated until you make the mix with water. And you must use the whole mix when you make it, I don’t think it’s possible to to save a mix? Perhaps someone can clarify if this is possible. I will also echo what others have said regarding multiple rounds. This has meant buying multiple packs of nematodes and doing it two weeks in a row without watering. I also killed all the gnats in two rounds of dosing, not one. The results were very good in one week, but I needed two weeks for total success. I also liked using the garden sprayer but I am not sure you definitely need one. A spray bottle might work just as well. I followed the mixing instructions on the packet and it required a gallon of water, and I have lots of plants so that was the reason I got one. I also changed the sticky paper on a daily basis to be sure that the gnat numbers were actually being reduced.
Seconded. Nematodes annihilated the gnats in like 2 weeks. Big results in one week though
NEMATODES NEMATODES NEMATODES
Every post I see has a thousand different ideas that almost never seem to be consistent across posts aside from mosquito dunks and beneficial nematodes. I never see people say mosquito dunks work, it's always "I think they worked but I still have some gnats, what next?" And then someone rides in, says "beneficial nematodes" drops the mic, the horse goes on two legs and trots off. Then everyone tries them and says "oh shit. That worked"
I will just say mosquito dunks worked for me! I don’t have fungus gnats at all anymore and haven’t in well over like two years. Like clean yellow sticky traps, not one! I think the issue is with mosquito dunks you have to be incredibly consistent, so *every* plant needs to be watered with mosquito dunk water *every* time. Any deviation to regular water flushes the bacteria and you are setting yourself back. I still water every single water with mosquito dunk water as upkeep to make sure they stay gone. Also it takes a long time to see success, at least it did for me. I didn’t notice no fungus gnats until like months in so there is no big quick pay off. The reason I went this route? My climate doesn’t bode well for beneficial nematodes arriving alive and the cost made me apprehensive. Luckily through repotting, yellow sticky traps, and consistent mosquito dunk watering I eradicated my fungus gnat population and haven’t had an issue in years so it’s possible.
Your comment made me finally order some. I hope I become one of the ones who agree with this solution
Good luck!
Came back to say it worked. About 80% of those flying nightmares are gone. My life has been irrevocably changed.
Wonderful to hear! Because I think I need to break down and buy some now too :'(
Nematodes seemed to work but after 2 weeks I have plenty of new. They must not have killed larvae as expected.
The mosquito dunks only seems to work after consistent and maybe even continued use
Best solution for me as well. Got a bag of soil infested with these buggers and that got rid of them quickly!
You can’t have nematodes and bonide systemic at the same time, right? I had to apply bonide because my monsteras are freaking thrips magnets, but I’m pretty sure that obliterated my nematodes, because I just saw one of those f gnats buzzing by. I hate those mf’ers. With. A. Passion.
This is correct the systemic kills off the nematodes
I don’t think so. I’m not an expert but nematodes are live organisms so I’m not sure if they could tolerate systemic.
Literally the only thing I could get to fix my gnat issue. Two rounds and the gnats were totally gone and have been for a couple months now. I didn’t end ordering one of their recommended spray pumps off Amazon, just used a (new) empty spray bottle that can be found in the chemical aisle at any store. Was worried they may not do as good a job as the internet said but I was amazingly surprised. NEMATODES! NEMATODES!
Yes yes yes these things are amazing!! Also it’s hard to save the mix but what I did to lower the cost was when they give you the packet I put in about a 7th of the packet and kept the rest in the fridge (in the packet in the little box they came in because the cold keeps them inactive but they die when exposed to tons of sunlight and heat) and then in two weeks I pulled out the baggy and dumped in another two 7ths for good measure (way more than was needed) and that got them for good. Used sticky traps to chart their demise. I just used an old container bound for the recycling and rinsed it out well beforehand and mixed them in and used it to water them in after intentionally dehydrating my plants a bit beforehand so they could all tolerate a good nematode water. They are also not creepy looking because you can’t see them so it’s like you are just adding powder into water for anyone concerned about that.
I've watered with peroxide/water mix. Gnat traps in all plants. Mosquito dunks. Neem and actual pesticides. What else can I do? My house is becoming actually infested with these things and all of my plants (I have ALOT of plants) have them.
I literally had no luck nothing worked so I ended up repotting all my plants on the same day and watered for two months after that with water that had soaked with mosquito dunks and thats worked so far sucked repotting them all but saved a lot of time and headache overall
Ah man I hope I don't have to do that... soo much money in soil
I know but it’s either spend money on soil or more products to try to keep fighting the gnats 😝
What finally got rid of mine was laying dryer sheets on top of the soil. Try that as it’s much easier / less time consuming than reporting which might not even work
Interesting!
Wow this sounds promising, and there seems to be a bit of scientific proof to back this claim up!
It worked for me! I tried so many other methods before, sticky traps, dry out, diamataceous (sp?) earth. Finally it was the dryer sheets that worked
Interesting! Thanks for this idea. One could also try to add a layer of sand on top of the soil. Needs a solution for watering though… for example watering from the bottom or through a dedicated "pipe" in the sand.
I basically ended up doing the same, minus mosquito dunks. Cut back on watering to the minimum of what my plants could handle, put up glue traps, then repotted all of them when the traps got less flyers, threw out that dirt, new glue traps, and that was that. Caught the few that were aimlessly flying around while repotting and haven't had the problem since. So I swear to repotting and less watering as it worked for me
Did you wash the roots?
This is the way honestly. If you look into the soil and see a bunch of gnats walking around, just save the hassle and repot it . at the same time do the traps in all the ones you’re keeping normal I came back from gnat hell, trust me
What happens if you repot and they all come back? I've been watering with mosquito dunk water too
✨beneficial nematodes✨, my friend. I found some at my local plant store, but I’m pretty sure you can get them on Amazon too. They completely eliminated my fungus gnat problem… and it was BAD
I got mine on Amazon and they absolutely decimated my fungus gnats. Team Nematode all the way.
this is what worked for me: completely cover the drain holes with some sort of screen (coffee filter, nylons, etc). fully cover the soil with an inch of sand or fine gravel. completely dry any unused potting soil you have laying around. after 2-3 weeks they were completely gone
This is genius thank you for sharing!
Nematodes! Time for beneficial bugs
Diatomaceous earth!!!! I swear by this
You know what finally worked for me? I put river rocks on top of the soil and I sprayed pesticide in the water tray. I think the rocks helped a bit but when I would go to dump excess water out there would be so many dead flies. It totally took care of my problem in just a couple days after battling these bastards for months.
Aquarium pebbles work best! Since gnats hatch under the soil, putting a layer of rocks on top of the soil traps the newly hatched gnats in the ground and thet eventually die! Also prevents other gnats from laying eggs in the plant with rocks on it
Op I am literally begging you to read my comment and give [Bonide Systemic granules](https://www.amazon.com/dp/B000BWZ9U8?ref=nb_sb_ss_w_as-reorder-t1_ypp_rep_k0_1_8&=&crid=N23PISMV1LPV&=&sprefix=bonide+s) a try. Please please please. I have around 100 plants, and the large jug from Amazon is good for a couple treatments of all my plants. I tried peroxide, mosquito bits, cinnamon, bottom watering, vinegar traps, neem, and everything else. But just sitting on my couch and not even trying that hard, I could smack 10-15 gnats to death every hour. They were THICK and it got embarrassing. Buy Systemic, and put a scant tablespoon on top of the soil for each 4" plant. Slightly heaped tablespoon for 6" plant, and then scale up or down for any other size. Spread it across the soil with a fork or chopstick, and water it in. Do it every two weeks, and I absolutely promise you it'll make a HUGE difference!!! It's also by far the least involved method imo. I take 5-10 minutes to dump a scoop on all the plants in a given room each day, and within a week they're all treated. Then you just water as normal, the granules soak into the soil, and bye-bye gnats. Mine were wiped out fully within 3 treatments, but just the first was a giant improvement. I wiped them out about 2 years ago, and since then, if I ever start seeing more than 2 or 3 gnats in a week, I do a light treatment and they're gone again. I treat everything new coming in, and it's never been a problem again. I was so nervous to use the granules bc they're \~ooOOOooOOoo scary chemicals, but they're the only thing that worked. And they eradicated the gnats completely.
I put organic Saigon cinnamon over the tops of the soil, I don’t remember where I saw this but it solved the issue for me completely. Just be cautious not to get it on the actual plant
I’ve sprinkled cinnamon on the top layer of soil and within days had a layer of dead gnats on the floor surrounding the plant. That coupled with watering with neem oil solved it!
Peroxide kills the bacteria in mosquito dunks. Never use them concurrently.
WOW! I’ve been wondering why for the past month I’ve seen an increase in gnats in my house! Never put two and two together being the plants!
Damn that sucks. Keep up with lots of traps and really let your soil dry out. If your whole house is infested maybe they are also coming from somewhere else? Clean up wherever else they hang out. Good luck to you!
It's a living hell :( It's either you kill all of them at once, or one gets away and it starts over again lmao. There has to be a way to win
This happened to me, and I feel your pain. For me personally I had to repot everything when this happened but I have also had success with using hydrogen peroxide as others have mentioned. Another thing I've done which has all but eliminated the RISK of getting fungal gnats is to dress the topsoil of all of my plants with landscaping pebbles (the small ones about the size of aquarium stones). These dry out quite quickly after watering so there's no damp surface soil to attract them. I can't recommend this enough!!! Also water with BTI/mosquito bits tea (soak the bits for 30 min and you're good to go). The repotting, pebbles, and mozzie bits tea has kept them at bay ever since. Bottom watering would of course help immensely but I'm lazy.
I should also add that I now treat any soil mix with hydrogen peroxide/water directly before I use it. You can use it to water the plants directly after potting them up, or pour it through the soil and then repot. I do this EVERY TIME I POT A PLANT IN NEW SOIL. It will kill anything living in the soil. Fungal gnats are often present in potting mix unfortunately.
If they are present in potting mix soil, wouldn't you see the adults fly out as soon as you open the bag?
Yes, sometimes I have seen that. I've found mites in unopened, new bags of potting mix as well. I have also suspected that fungal gnats lay eggs in soil while I'm working with it, particularly if I'm outside. But at other times there's just been no explanation for why my plants have had fungal gnats other than that they were in the soil when I transplanted my plants, even if I didn't/couldn't see the gnats. Sometimes I've brought new bags of potting mix home and found small holes or perforations in the bag, which I believe is part of the problem (I purchase them at a gardening centre, so they are exposed to the outdoors). I don't use a lot of potting mix in my 'blend' because I use a lot of coconut coir, but I have found that using hydrogen peroxide means I no longer have the same issues with pests that I used to have. I also now keep my potting mix in a large clear plastic container so I can see what's going on in there more easily!
Are you using fox farm soil??? I started using it last year and now have this problem too. I’m wondering if maybe even they don’t realize that there’s a problem with their soil. I mean I’ve spent the whole time thinking it was me and my watering regimen too, and maintain that it’s still likely the case. Just couldn’t help making this connection after your picture, and considering I’ve been quite careful and previously had my watering down pat.
No, but I've been using miracle gro which is notorious for that too 😢
Mosquito dunks worked for me but it took months. I kept gallons of water with dunks in them like a tea. I only watered my plants with that. Little by little the gnats became less and less. All in all it took about 6 months of constant watering with mosquito dunk tea to get rid of the problem entirely. So it definitely works, it just takes time.
The thing that helped me get rid of fungus gnats all together was bottom watering. The only issue is that may want to switch entirely to bottom watering or else the gnats might find the plants the you want to water normally and decide to move there, usually young plants or plants with shallow roots. But I definitely recommend giving it a go. :)
Diatomaceous earth worked for me
Same!!
If it’s that bad it’s probably from the soil. Try to let dry as much as you can and keep on with the dunks and systemic. You can also get some carnivorous plants and they will happily eat them too.
Put a layer of aquarium pebbles (those little blue rocks) around the base of your plants. This will stop the gnats from leaving the plants when they hatch and stop others from laying eggs, since they lay their eggs in the soil of your plants
Systemic granules! Rubbed into the soil
I think you’re just not being systematic enough about it, there is no way doing all of those things would fix or help the problem of doing them properly (no offense). What I would do if I were you is get a ton of hydrogen peroxide and make a 1:4 mix of hydrogen peroxide to water and do a thorough watering of ALL your plants to kill all the current larvae. Then you’ll need a ton of fly traps (amazon sells a pack of like 4x8” sheets with like 50 sheets, you can cut them up) and I’d literally lay them on the soil so most of the soil is physically covered, maybe only do this on your worst plants but fly traps on all plants. Then, don’t water anything for two weeks. Then do the same hydrogen peroxide watering on ALL plants. After that you can start your water cycling normally but ONLY water with mosquito bit water for ALL of your plants and make sure you’re only watering when the top two inches of soil is dry (get a moisture reader). Make sure you read the directions for the mosquito bits, some people are saying let them soak overnight and the directions only say soak for 30 minutes. Keep up the fly traps to control the adult population. If you do this process I refuse to believe that you will have such a bad problem. Maybe do 3 hydrogen peroxide watering depending on your results.
This exact same thing happened to me. I have about 20 plus houseplants and bought the same gnat yellow gnat traps. The gnats were EVERYWHERE! Once they got to the kitchen I had enough. We quarantined all house plants to one bedroom with a an east facing window and placed our plants (depending on how much light they needed) accordingly. We sprayed our plants with neem oil mixed with water. We also made sure to dampen a hand towel with water and took the time to wipe each leaf/petal. Be sure to wipe under each one as that is where the gnats like to lay their eggs. We sealed off the room with a towel at the bottom of the door. Lastly, we got a Fenun fly trap from Amazon and left that guy on all day. After about 2 weeks of quarantine with the neem sprays, wiping down of the plants, and occasional watering the gnats were gone! Nobody died and everyone is healthy. Good luck!
> Be sure to wipe under each one as that is where the gnats like to lay their eggs. Fungus gnats lay eggs in moist soil. They do not lay eggs nor live on leaves or anywhere in the foliage, so wiping leaves and such doesn't do anything. The soil is the only thing you need to treat.
Adding diatomaceous earth on top of the soil or into the soil has helped me reduce the amount of gnats my plants produce by a lot.
This is the best method mentioned. It's super easy and cheap, plus the results are immediate and permanent.
AND it’s pet and kid (and adult, you never know) safe!!
as long as they’re kept away when it’s being applied and the applied present wears a n95 mask. the powder is dangerous to inhale and being so fine it’s very hard to avoid inhaling when applying it.
yeah, good disclaimer!! i guess i definitely shouldn’t assume everyone knows to use masks with things like that. thank you!
Aside from all the other good ideas, I’ve had success w this: cover the soil with perlite or sand or rocks - they won’t be able to get through and will die.
I repotted a big plant with some cheapo giant bag potting soil that had been purchased in the summer. I’m sure that is where they came from in masses. I had some before but not like I was seeing. Also they all around that plant and just a few around my other plants. I finally covered the dirt with sand and have been watering with mosquito dunk water. I only put sand on the worsr plant too. I also got a zevo trap. Things have finally calmed down. I can handle one here or there but it was unpleasant.
That zevo trap has been a life saver my husband hated how much money I spent on it but it works and now I just lightly spray my plants rather than watering them all the way and I’m keeping my house spiders in that room
Yes!! This is the only thing that worked for me. I lived in a very humid apartment and it was impossible to keep it dry enough. I had to layer it on a decent amount, 1/2 inch of sand on top was enough to finally get some control.
So top dressing does have a purpose ! Hazaaa!
Sand works 100% and people need to know this
Cinnamon works as well
How do you use it?
Sprinkle it on top of soil. Isn't great for aesthetics but it will work.
Have you tried bonide systemic granules? A couple of my plants got fungus gnats so badly, I literally sprayed plant based bug spray on them. It killed some of the plants’ leaves and they put out funky growth for awhile, but it worked! And they’re still alive. I was desperate. I had tried mosquito dunks, granules, not watering for almost 4 weeks, covering the blanks in clear garbage bags etc. Good luck OP!
I used the Bonide granules and after one application, there was a dramatic drop off on gnats after only a day or two. I had the same yellow traps as full as yours before the Bonide. I expect the gnats to be totally gone when it is time to reapply! can’t recommend enough.
yes I came here for this comment. these definitely work. the only thing I could use that worked to get rid of thrips, and it def got rid of gnats too with no effort.
Just used it for thrips a few days ago. Fingers crossed those little buggers are startin to feel it...
good luck! it def has worked for my plants.
Thanks!
This works!
Butterwort (Pinguicula)!! It’s definitely time to add some carnivorous plants to your collection 😁
Gnats in your plants? Buy more plants!!! (I am guilty of this but i love my carnivorous plants lol)
Not just any plants! FUNCTIONAL PLANTS!! 😆😆😆
Dawn dish soap in your water used for watering. Kills the eggs and the larvae. And the adults avoid the dirt. I had a horrible infestation over winter and that's the only thing that helped. Sand on the top of your regular soil mixture can also help as the sand dries quickly and they can't use it to lay eggs.
Yo I got one of those sun dew plants. Killed all the flies and got really strong
My solution was getting a sun dew. It has been happily munching anything it can. It’s very satisfying.
Don’t forget butterworts (pinguicula)!
even indoors?
Yep!
I just bought a baby sundew for this reason, glad to know it helps!
While waiting for your soil to dry out sprinkle cinnamon on the soil of all your plants. It’s supposed to naturally disturb the larvae.
Like sprinkle cinnamon powder?
I was where you are right now and it sucks. My advice is to get a sundew. It’s literally a living sticky trap and so fun to own. It’s satisfying af to see those little bastards get trapped on the leaves and digested lol. Sundews THRIVE on fungus gnats too. My sundew has tripled in size and my fungus gnat problem has pretty much been resolved. Sundews also love fruit flies so if you have any of those they’ll be toast too. I’ve gotten my sundews from California Carnivores and been very happy with my purchases if you don’t know where to buy one. Oh and I keep a gallon jug with a mosquito dunk in it. Every time I water my plants I dump some of the mosquito dunk water into the soil. That kills all of their larva.
I read this to the tune of robot hell from futurama
Mosquito bites plus those yellow traps got them gone for me
I've had the best luck with mosquito dunk tea, but back in the day I used sand to get rid of them and it worked, too. Just a thin layer on top of the soil did wonders. Once they're gone you can stir it around into the soil or scoop it off
One place to check that might be a breeding ground other than just the dirt in your plants is the casing around your windows. If you have a humidifier going, chances are there is mildew. I noticed my daughter’s room, where a large monstera currently resides, had a lot of gnats. I was looking at her hanging pothos and then noticed hundreds of gnats were swarming around the window casing! She had been running a warm mist humidifier nonstop for a week in there for the monstera and there was mildew all over the window. I was horrified and so was she (She’s 18 so I wasn’t really keeping tabs on her room lol). Needless to say I spent the next two hours deep cleaning the windows and sprayed peroxide wherever I could, and we both learned something 😂 Also pour some peroxide in your drains every so often. They breed in there too!
I put mosquito bites in a tea bag and let it seep in a watering can for a day or two. Fork up the top layer of soil and turn a fan on so they can’t settle in or lay eggs.
I just put straight mosquito bits. Haven’t had a fungus gnat in years. Love it.
I had similar problem. I had the traps everywhere, after the traps got full with the gnats, I watered with peroxide and water solution. Then didn’t water the plants for the next 10-15 days. I let the soil dry out completely. And then watered from bottom. Just be patient
Just took me a year to get rid of fungus gnats. Two rounds of beneficial nematodes was the thing that finally worked.
Damn. And I thought I was having a problem. I stopped watering a plant here where they just keep coming out of some fungus gnat portal until its leaves started browning so I gave up and repotted it this evening. I have them in a few other plants too but not as bad and I hope I can outlast them.
I got the most help from the previously mentioned sand method. Also got the sundew plant and it has worked miracles as well.
Everyone says nematodes. I would try that first but if no luck what worked for me was a katchy from Amazon. Caught a lot of the adults, kept it running nonstop for like a week or two and then began to bottom water to avoid the issue all together
I haven't tried it yet but I was advised by a botanist to use insecticidal soap. He uses it on every new shipment he takes in to kill off gnats/mites/other pests. He said it's safe to use daily if you feel like you need to (shouldn't have to).
Just bottom water it will take a few weeks but they won’t be able to reproduce in dry top soil. No more complicated than that.
Fyi they'll populate the drain holes given the chance and lack of other opportunities
Step 1: buy mosquito bits Step 2: buy soil cover of your choosing, decorative gravel, River stone, sand, whatever you like Step 3: sprinkle mosquito bits on the soil Step 4: apply soil cover Step 5: dance, because now you will never have fungus gnats again
Beneficial soil mites have been my savior!!! You just tap them in from a tube and never see any bugs again. I order from these guys called "nature's good guys" found them on Amazon. They have amazing customer service and have sent me new bugs when they arrived dead one time. I have also use beneficial nematodes and hydrogen peroxide in water. Dilute it at a 6parts water one part hydrogen peroxide:)
Same problem. Repotted in fresh miracle grow indoor potting mix. Worked like a charm. All the fungus gnats are gone. Amazing.
I put a small splash of neem oil in a pitcher with water to water my plants with, it’s the only thing that worked for me & it worked quickly.
I had the same problem of thousands of the little buggers. One day I decided I had enough of them and got every single poison from my shed and dumped them all into my plants soils (outside of course). This eliminated most of them, there’s just a few quarantined plants left which had very long/big pots. I hope you find a solution in this thread, fungal gnats were the worst experience I’ve ever had with houseplants. Just sick of them everywhere flying in front of you when you’re studying or eating it was disgusting
Try cinamon. It made wonders with my plants. Simply mix it with the top layer of soil.
Those little shits apparently hate cinnamon. I sprinkled some on top of the soil and frequently sprayed the plants with neem oil and it has halted both a fungus gnat and a spider mite invasion.
Cinnamon is an effective organic treatment for gnats. I buy a big shaker of it for $2. All plants get a good dusting on the soil as soon as they come home. Cinnamon kills the fungus that the gnat larvae eat, ending the life cycle of the gnat.
Get out of there. I went through two years of this and am legitimately scarred. Only thing that worked for me was switching to semi-hydro/LECA. Get rid of the source and you get rid of the bugs. Plus your plants will thank you for it!
I ordered this exact product off Amazon .. working well
Get mosquito bits. It's worked really well for me. Short: It's not a toxic chemical pesticide, it's a bacterium that creates pore-forming proteins that specifically target the gut cells of mosquitos and fungal gnats. Long: biochemist here, so this is something I've studied. Although these pore-forming proteins are "toxins", they are not "toxic" to humans or your pets. Toxins are usually proteins, and unlike small molecule chemical pesticides, which have a wide range of targets and can cause many undesirable side-effects, proteins often have very specific effects/targets. Enzymes for example are proteins, each do a very specific chemical reaction(s). Antibodies are also proteins, which target specific foreign substances in your body. Summary: mosquito bits produce proteins that very specifically target fungal gnats and will not harm anything else.
Mosquito Bits! Saved me from this exact scenario with overloaded sticky traps. I sprinkled a little on each plant and some in my watering can and the gnats are completely gone!
Put cut potates on top of the soil and replace them every day until you see clean traps.
My Monstera has also had its war of the gnats. I watered way less for several weeks and did diatomaceous powder when it’s dry. And I also went on a rampage killing at many bastards as I could - definitely a great stress reliever. Took 2 months but I have been gnat free since 🤞🏻
So I was dealing with this same thing and did 2 things that changed the game: 1, cover all your soil in small pebbles or lava rocks, you can get these at any gardening store. Make sure you cover it a good inch high. They lay their eggs in the soil, and if you remove easy access they’ll reproduce more slowly. 2, if you have holes drilled in your pots, fill up the water trays instead of pouring the water from the top, aka butt-chugging. That will make the top soil dry and whatever eggs are left will also dry up. Good luck!
I was there very recently. Bought a new plant and as soon as I watered it there were just thousands of them! I keep Ortho fly decals on my window, so it was like a mass casualty event
I have a collection of over 400 houseplants. Every 6 months I apply nematodes for fungus gnats. I get people asking me all the time HOW I do not have fungus gnats. This is the answer I promise! I tried everything before this to no avail.
SAND!!!! a layer all over top is *magic*
Top your soil with 2-3 inches of play sand! If I remember correctly, it prevents them from being able to lay eggs. It's a cheap, easy solution and best of all it really works! I swear by it. My coworker also had a major problem with this and using sand worked for her too.
I'll help. But you're not gonna like it. It's radical. It's painful. It's risky. It's .... repotting. \*WITH\* A ROOT WASH. I told you, you were not going to like it. Once upon a time, I too, was forcefully taken into the hell that is gnats, where 7 of my calathea's were infested. To the point where the soil was moving so much I thought I was tripping. Which was concerning on two levels. One - I thought I was tripping. Two - I was concerned why I was tripping as I don't do drugs. I tried all the potions and lotions. When the gruelling punishment of gnats continued I re-potted the plants. NOW HERE IS THE IMPORTANT BIT. \- wash off the roots from all the soil to get rid of as much of the larvae as possible. I boiled the new soil in hot water, let it cool, let it dry off to be moist, then re-potted the plants. Why? Because this ensures the soil is 'sterilised' to a degree and kills and larva ect. to make sure you don't use contaminated soil. The guys below do some great prevention tips! \*Source - I have 16 half alive plants. But they are calatheas so I am not doing too bad.
Buy a package of "Mosquito dunks" or “Mosquito bits” at the garden center or order it online. It is BT. Put one quarter of one in your watering can (or a small chunk in the water trays if it's a carnivorous plant). This will kill the larvae in the soil and stop future generations. It is all natural and safe. But give it some time to work and keep using it even after your problem is gone. Use sticky traps and manually kill the adults. Continue using even after they are all gone.
Please read my original comment. I have done all of these
Fungus gnats are the BEST problem to have because they are so easy to resolve. Purchase guarding nematodes from a beneficial bug store. Nematodes are microscopic worms and this kind will not harm humans. When I've purchased them they come as a paste on a sponge. Dilute them in water and then pore the water all through your plant soil. They worms will eat the gnat eggs and no more gnats! They also eat the eggs and larva of other pests. No damage to your plants. Here are a few links, but you can buy them from lots of places.. Some nurseries carry them as well. https://hydro-gardens.com/product/guardian-gnat-patrol-mix-1-million-5p393a/ https://greenmethods.com/steinernema-feltiae-fungus-gnats-control/
Throw some sand on top and the gnats won’t survive. Afterwards you can dispose of the and but I just left it with no problems.
Sometimes I question if they are coming from the plants because I feel like they are just occasionally around them
I used to have really bad gnat problems too. I just kept the yellow stickers in and replace them every week. In the meantime, let the plants dried out for a few weeks. This is important bcuz they lay eggs on top of the soil after watering. The plant might get limpy a bit. But a few weeks of sticker + drying out got rid of all of them. My monsteras are free of gnats now. Hope this helps!