The ever dreaded fungus gnat

luv2gro(z3a AB)April 18, 2006

About a month ago, I went to buy some chamomile tea to do some damping off prevention and when I got home, discovered I had bought peppermint tea. After a bit of a ggogle, I discovered some sites talking about peppermint tea to ward off fungus gnats. I then did a drenching with peppermint tea and just realized tonight that I have not had any, and I mean any, fungus gnats this year. Last year, I was going crazy with them and had gone through about 6 sticky strips by now and even got some industrial insecticide from the greenhouse I was working at. That helped a bit but they were so out of control by then that I just couldn't wait to get everything outside and the greenhouse turned off.

I'd be interested to hear whether it is just my lucky year or if the peppermint tea really worked. Is anyone having a problem with fungus gnats right now? Would you be interested in trying the peppermint tea on your next watering of everything and letting us know if it at least helps the problem? If it works, it's a lot cheaper than the mosquito Bt products. Thanks

Shauna

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northspruce(z3a MB CDA)

Shauna, thanks so much for bringing this up.

"Do I have fungus gnats?"
YES!!!

"Do I want to participate in a pepperment scented experiment to rid myself of them?"
YES!!!

Operation Gnat will commence this evening if I get a chance to haul butt to the grocery store and buy some tea.

Gosh you have no idea how many gnats I have. My first batch of starter mix must have had eggs, and it's like gnat club med for them in my basement. I have gone through 2 boxes of Sticky Strips, throwing them out when they're too full of gnats for any more to stick.

Will keep you posted. You know how I like a good experiment ;0)

    Bookmark   April 18, 2006 at 11:20AM
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luv2gro(z3a AB)

Thanks, Gil. You may have to do a couple of waterings to break the cycle but it may be that this killed the larvae for me right off the bat.

A suggestion: Try some also in a spray bottle and spray some on the nasty little flying Moms & Dads and see if it kills them on contact. Our own homemade Raid for fungus gnats. - A tea party - how nice. Eeeeeeeek - peppermint tea!

BTW, I used about 1 tea bag per litre of water, I think and used boiling water, let it steep and then cooled it off overnight.

If it doesn't work, we can talk about apple cider vinegar. But this is only an attractant, not a cycle breaker.

Shauna

    Bookmark   April 18, 2006 at 11:55AM
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CrazyDaisy_68

Sounds like a great idea Shauna! *** puts peppermint tea on shopping list! ***

I'm wondering if this will help with other bugs outside this summer too... worth a try anyways!

~Ang~

    Bookmark   April 18, 2006 at 3:12PM
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luv2gro(z3a AB)

Could be right, Ang. It didn't seem to do any harm to any of the seedlings that I had up at the time - petunias, lisianthus, various grasses - all of the stuff that I started early.

Shauna

    Bookmark   April 18, 2006 at 3:36PM
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north53 Z1b MB(zone 1b Canada)

I'm not having any trouble with fungus gnats this year, but have been waging a battle with aphids (at least I think they're aphids) all winter long. So far they don't seem to have done any damage, but that's probably because as soon as a new batch breaks out I spray everything with insecticidal soap. But it's getting tiresome, especially now that they seem to have spread to my new seedlings. I think they originated with a coleus I brought indoors in the fall.
But thanks for the peppermint tea hint. I know I haven't seen the last of the fungus gnats.

    Bookmark   April 18, 2006 at 5:15PM
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CrazyDaisy_68

north53, I was just reading about citrus for aphids. You boil some water and orange or grapefruit (or whatever citrus) peels. Let that water cool and spray it on the aphids. It has to make contact with the aphids to be effective. I haven't had aphids this winter but I know that I will again at some point.

~Ang~

    Bookmark   April 18, 2006 at 7:41PM
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savona(z2bBCCanada)

I had my own battle with fungus gnats earlier this year. I brought them into my plantroom when I moved the cuttings from the greenhouse inside..I wasn't concerned at first..swatting and slapping them when I could catch them, there never seemed to be many, The problem started when I had seedlings popping up..they mowed their way through the lisianthus and started on the delphs..I was desparate and read the label to a container of wilson's soil dust..googled for information and then sprinkled my containers..no more gnats..bbbbuuuutttt..some of the seedlings hated the soil dust..some seem to be stunted afterward and some didnt seem to react to it at all..about 9 days later I seen one lone gnat and sprayed "konk" from the doorway of the plantroom as far as I could get from the plants,I didnt see the gnat after that..I was told afterward that cinnamon sprinkled on the soil seems to deter them from laying eggs but the lisianthus container was sprinkled and it didnt make any difference at all..I would love to know if the peppermint tea was the answer as it is a much healthier one then what I did...savona

    Bookmark   April 18, 2006 at 7:48PM
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northspruce(z3a MB CDA)

Well I watered with peppermint tea last night and the night before, and the fungus gnats all have fresh breath. LOL kidding. Actually this is very unscientific but I see very few adults flying around. Perhaps as the sticky strips catch them, they are not being replaced? Hope so!!

Plus when I was watering (teaing?) a huge wood louse scurried out of my venedium tray and looked super P.O.ed. So maybe wood lice don't like it either. I don't have many of them left either, I vacuumed a bunch up.

    Bookmark   April 21, 2006 at 9:52AM
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luv2gro(z3a AB)

Keep monitoring the situation and let us know. Give it a week and then do another watering with it to break the cycle. I am pretty sure (unscientifically speaking, of course) that this works. I still don't have any. NADA. Not a one. If we have found our answer, just think - no phtewwwyy, phhtt, slap, slap, sticky trap fingers, or cider vinegar smelling greenhouses anymore. Fresh breath or not, I'd rather have a bad breathed butterfly.

Shauna

    Bookmark   April 21, 2006 at 12:58PM
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prairierose

I'll be trying the peppermint tea for sure. I read years ago that watering with tea would kill the fungus gnats, so I do water occasionally with regular tea. It helps, but isn't a cure. Peppermint tea sounds like a great idea.
Connie

    Bookmark   April 25, 2006 at 1:39PM
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luv2gro(z3a AB)

Thanks, Connie, for bringing this up top again. I was just going to do that myself.

Gil, any luck? Has it eliminated some of the problem? Can you breathe again without getting a lungful of gnats? Anyone else tried it and what are you finding out? I'm anxious to see what happens. I still don't have even one flying little pest, that I have seen. Keep up the research. We could be on to something big here. : )

Shauna

    Bookmark   April 25, 2006 at 2:09PM
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northspruce(z3a MB CDA)

Shauna sorry I didn't mean to ignore you, I just forgot to reply.

In the basement, the peppermint tea has definitely reduced the gnats. There are just one or two flying around when I blow on the flats. I plan to keep watering with it periodically in case they have more larvae or something.

However, I also watered my upstairs stuff which mostly includes caladiums and tomatoes, and there are still clouds of them. But there are houseplants nearby that didn't get watered with the tea so perhaps they are fueling the gnat population. I will have to water everything next time I guess.

    Bookmark   April 26, 2006 at 9:08AM
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CrazyDaisy_68

Out of curiousity, I just did a google search for "peppermint for bug control" and its amazing how many sites come up! Neato! I really think you are onto something here Shauna!

~Ang~

    Bookmark   April 26, 2006 at 10:12AM
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luv2gro(z3a AB)

Yippeeeeee!!!! I thought it had to be the tea. Let's keep the observations up and maybe we can rid the world of the pesky things. Might be some others, as well, that disappear along with them.

Shauna

    Bookmark   April 26, 2006 at 11:02AM
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ramazz(8a VA)

Hi, I just wanted to mention that I tried watering my seedlings with chamomile tea and the gnats flew away immediately.

    Bookmark   May 11, 2006 at 2:29PM
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fancygardner

Hey, tried the vinegar works to attract. I hear diatemacous earth in the soil will kill larve. I have not tried the pepperment tea but will do it all. I want to knwo if I should change soil to organic or not. Just want to get the larve and adult gnats. Thanks for replys.

    Bookmark   August 4, 2007 at 1:04PM
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axak

we have been at war all night - we waged an attack of cinnamon and now working on boiling water for tea.
We will try the peppermint and report back...(we also laid out bowls of OJ and they seem to be enjoying the deathly swim)...BUGGERS!

    Bookmark   December 17, 2007 at 12:18AM
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luv2gro(z3a AB)

Last week, I made some peppermint tea and used it in my big alstroemeria pots and my mandevilla pots that I'm also overwintering. I had been noticing some gnats flying around the house of late. They are gone. No more fungus gnats again. This is definitely a method that I'm going to use for years to come.

For those of you interested in trying it when seedling season is upon us, start watching the grocery stores for when tea is on sale and stock up. Not sure if you can buy tea at the dollar stores, but that might be a cheap source, too. I'm not a tea drinker, except for the odd cup of green tea, so I haven't had any real preference to what I bought - just the cheapest. And I bought about 6 boxes on sale and keep it in the freezer.

Shauna

    Bookmark   December 17, 2007 at 3:31AM
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glen3a(Winnipeg MB 3A)

One thing to keep in mind is that they apparently feed on organic matter in the soil (and occasionally plant roots if in large numbers) and lay eggs in moist organic soil.

Apparently, if you let the soil dry out well between waterings this goes a ways in controlling them as the tiny larvae will dry up and die. Of course, sometimes that's hard to judge as some plants don't like to be too dry between waterings and sometimes what seems dry might still have fungus gnats.

I am wondering if something like Neem oil mixed with water and watered into the soil would help? One year I was so desparate and they were all over the house that I watered my plants with cygon mixed with water, but now I'm in a "not using harsh stinky chemicals" phase.

My fungus gnat problem seems to appear every spring whenever I bring out the new potting soil and start seedlings. I wonder if leaving the potting soil in the frozen trunk of the car would help? I know they say to buy only sterilized soil, but I think all you need is one new houseplant with a few in there and then you have those little flies in all your houseplants.

I find the gnats tend to fly between plants but also toward the light of the windows. Sometimes if I have a glass of water on the windowsill, say with plant cuttings in it, there will be a few drowned in there. So, maybe a glass of water with bit of dish detergent, placed on the windowsill would attract them to drown?

Glen

    Bookmark   December 23, 2007 at 8:37AM
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luv2gro(z3a AB)

Cider vinegar diluted about 50% with water is an attractant to drown them, Glen. I used it in my greenhouse one year and drowned hundreds of the pesky things. I believe it has to be the cider vinegar - not white vinegar.

Honest. Try the peppermint tea. I'm absolutely convinced that it kills the larvae without harming the plants and using any nasty chemicals.

Shauna

    Bookmark   December 23, 2007 at 5:26PM
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marciaz3 Tropical 3 Northwestern Ontario

I've put bags of soil outside too to try and kill off the gnats. Nothing more frustrating than hoping to plant something and then having a bag full of gnats! I've tried the cider vinegar for fruit flies (bumper crop this year) - it works to a certain extent, but i never seem to get all of them.

    Bookmark   December 24, 2007 at 8:45AM
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tom__alaska(zone 2/3 AK)

Another way. If watering with a 1 gallon watering can, pour a teaspoon(approx)of dish soap (like Dawn) on top of the water. It smothers the little #$#$@#$%$#.

    Bookmark   January 4, 2008 at 2:22AM
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tom__alaska(zone 2/3 AK)

A good story about the gnats!
In a wanna be fancy restuarant I ordered a glass of red wine with my prime rib. The wine was lousy and when I asked to see the bottle was told it was in a box. At that moment a nice little gnat came by and promptly fell in the wine glass. Nothing like a gnat doing the backstroke in your wine glass to get the waitress to offer a better glass of wine!

    Bookmark   January 5, 2008 at 1:04AM
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valleyrimgirl(2b)

A few years ago, I had a housefly in my soup at a well known restaurant in Winnipeg. That fly gave me a free meal.

It is amazing the 'power' of a little fly. :)

Brenda

    Bookmark   January 5, 2008 at 11:07PM
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silverbug(5)

So, do you think that the peppermint tea is safe for tomatoes and peppers and other veggies? I put cider vinegar in a jar in there, but they aren't interested AT all. Not even one is drowned in there. I have a nice little swarm in my organic soil and all over my tomatoes and peppers. :(

    Bookmark   April 22, 2008 at 10:05AM
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gladzoe(3a)

I had plenty of them drown themselves in my vinegar shaker in the kitchen, so they don't mind that stuff either. I will try the peppermint tea.

    Bookmark   April 22, 2008 at 3:35PM
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marciaz3 Tropical 3 Northwestern Ontario

Try the yellow pest strips, but just be careful that the leaves of your seedlings don't catch on them!

    Bookmark   April 22, 2008 at 3:36PM
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dita

PEPPERMINT TEA ROCKS MY WORLD!!!!
Many thanks for posting. I have been exceptionally frustrated with these midges flying about and feared that they would infest my other plants.

I have 'rescued' the soil in my lovely hibiscus and oleander with this mixture :)

    Bookmark   January 24, 2009 at 1:38PM
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marciaz3 Tropical 3 Northwestern Ontario

Isn't this funny! I checked out this old thread this morning, too, for my daughter who phoned me in a panic about all the bugs in the soil of her lemon tree. She has peppermint tea and has begun treatments. :) I also brought her some sticky strips to catch the live ones.

    Bookmark   January 24, 2009 at 10:24PM
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sengyan

Very interesting. I may have missed it - the amount of water for 1 peppermint tea bag. Would it work if one add a few mint leaves (fresh or dry) to steep with a tea bag. Peppermint tea is a little too expensive for someone on a fixed income.

Sengyan

    Bookmark   January 25, 2009 at 5:50PM
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marciaz3 Tropical 3 Northwestern Ontario

Try it, Sengyan, and let us know if it works.

    Bookmark   January 25, 2009 at 9:14PM
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sengyan

Will have to wait till spring/summer before I can get mint leaves. One I've tried it I will post results.

Sengyan

    Bookmark   January 26, 2009 at 3:47PM
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prairierose

I used the peppermint tea trick a couple of weeks ago. I didn't have much for fungus gnats, but they'd appear once in a while. I watered all my house plants, and haven't seen a gnat since.
Connie

    Bookmark   January 27, 2009 at 12:37PM
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sengyan

I didn't wait for summer. I bought a bottle of mint and peppermint extract and made a solution of 1/2 L and 5 drops of the extract. This is way cheaper than buying mint tea.I sprayed every pot in the house. My wife thought I had gone off the rocker. It is hard to see the result because the infestation was waning. I did see one little bugger fall and lay still. I'm waiting the the next hatch to happen and I'll know if it works.

Sengyan

    Bookmark   February 1, 2009 at 4:08PM
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prairierose

The extract sounds like a great idea, Sengyan. I don't mind making the tea because I have my own mint - I keep an icecream pail full of leaves in the cellar - but the extract would certainly be a lot faster to prepare.

Connie

    Bookmark   February 2, 2009 at 2:00PM
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dirtdigr(5)

Is anyone having any luck with this? I have a few in my greenhouse and I'm wondering if this can be used for seedlings as a spray? Or should I just water them with a cooled peppermint solution. Do you need to dilute it? Are you making it a strong tea?

I just joined and I can't believe what a gold mine these forums are!

Tessa (aka dirtdigr)
Visit me at my blog...

Here is a link that might be useful: Blunders with shoots, blossoms 'n roots

    Bookmark   February 7, 2009 at 12:31AM
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elektrobubblez(5 MI)

has anyone else had the same luck with the peppermint extract? i am going absolutely insane over these fungus gnats....

    Bookmark   February 10, 2009 at 10:13AM
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sengyan

I am in the midst of an experiment with peppermint extract. I have 2 small trays of germinating flower seedlings in a glass-covered aquarium and a new hatch of the pesky things are flying around in the aquarium. Since they are in the aquarium I control them. It has been 3 days into the hatch. I spray 2 -3 times each day. I think the spray killed/rid off the knats everyday. I believe the pests I see daily are new hatchings. Now all these are unscientific, personal observations. I will report every few days until the hatch is over ( when I don't see any flying around in the aquarium for 2 - 3 days). Is anyone else using the extract? Please report.

Sengyan

    Bookmark   February 15, 2009 at 1:40PM
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sengyan

Follow up. The news about peppermint extract is not good. I trapped a gnat in a clear plastic pill container and sprayed it. It was alive after 2 hours. I doubled the strength of the spray and sprayed it again. After another 2 hours, I then tripled the strength. After 2 hours the little rascle is still alive.
The experiment is a failure.

Sengyan

    Bookmark   February 19, 2009 at 6:22PM
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oilpainter(3)

If you have fungus gnats a mild soap solution will kill off the larva in the soil but it won't kill the gnat so you have to do it a few times. To prevent having them in the house steralize your soil. 30 minutes in a 200 degree oven will kill gnat larva and any fungal spores. I use a tin foil roaster to do mine

    Bookmark   March 26, 2009 at 8:45PM
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oilpainter(3)

Hey all you peppermint users. I did a little research and Peppermint has a large amount of Menthol. They are trying it out on lumber as an environmentally friendly alternative to pressure treated stuff. If it keeps bugs and rot from setting in it must kill the lowly fungas gnat

    Bookmark   March 27, 2009 at 1:30PM
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wrynsmom(5)

Are we using "herbal" peppermint tea or Just peppermint black tea?

Thanks,

Carolyn

    Bookmark   July 22, 2009 at 1:51PM
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marciaz3 Tropical 3 Northwestern Ontario

Herbal, Carolyn.

    Bookmark   July 22, 2009 at 3:36PM
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wrynsmom(5)

Thanks so much, marcia3! :)

    Bookmark   July 23, 2009 at 12:39AM
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wrynsmom(5)

Okay, the tea did NOT work for me. They just kept hatching and growing & didn't give up. I opted for Neem oil.

But it sure sounded good!

Carolyn

    Bookmark   August 1, 2009 at 12:07AM
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fragrantflower

Eucalyptus oil seems to repel them. I used 20 drops in a liter of warm water and sprayed on the top layer of the soil. This works only for the adult ones.

    Bookmark   November 28, 2010 at 12:36PM
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intotheark

Last year I lost hundreds of cuttings and seedlings to these
little scourges. By the time I realized they were fungus gnats (thought they were just fruit flies) it was too late.
The worms (maggots) love tender young feeder roots, hence the complete loss of most and the unrecoverable stunted growth of the 'survivors.
Drying the soil serves to put the gnat 'maggots' into a type of stasis not death;
but upon a soak of neem oil should kill the worms, I don't know about a peppermint tea soak.
A mix of peppermint tea and a dash of soap (for leaf/bug adherence) should kill the adults and repel them from entering the soil to lay eggs.
I use a mix of Dr.Bronners Peppermint soap, and garlic for aphids, adult gnats, whiteflies, etc. outside, as the smell is strong.
Vigilance and early detection is key for these monsters.
Happy hunting.

    Bookmark   December 26, 2010 at 3:30AM
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marricgardens

I get a lot of fungus gnats each fall when I bring my plants in for the winter. After trying a few things that were mentioned here, I decided to try Safers Sticky Sticks. They worked great! Because I have a large area to contend with, it can be expensive buying those all the time so I went to the dollar store and bought some yellow poster board (the craft paper used in kids crafts). After cutting it into the appropriate size, I smeared each piece with vaseline and used the sticks I already had from the Safers pkg. I had bought. I put two in each flat and that way I can catch quite a few. This can also be done on larger hanging sheets for white flies and aphids. Marg

    Bookmark   December 27, 2010 at 9:20AM
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swontgirl_z5a(5a)

Marg,
What a great idea. And the vaseline wouldn't be as sticky for when I bang into them! I am constantly putting those darn things back in the sticks because I have stuck to them when I'm watering or moving seedling cups around. I will have to try it this winter.
Another good trick is if you have your plants where no one really goes you can keep some old sticky strips from last year and use them again when you bring in your fall plants. My plants are in an unfinished part of the basement and I keep a few pots with old strips stuck in them to use in the fall.By the time I start my new seeds the fungus gnats have all been caught.

    Bookmark   December 31, 2010 at 6:02PM
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rowepolyid_gmail_com

Here's another trick. Most clear, plastic bottles (apple juice, etc.) have an indented bottom. Cut the bottle (scissors or knife) about two inches above the bottom. Spread vaseline or Tangle Foot on the top of the indent and fill the "moat" around it with apple cider vinegar (to below the central sticky indent). The gnats are attracted to the vinegar and get stuck on the coating or drown in the vinegar. Just refill the moat with water occasionally to dilute or reconstitute the vinegar.

    Bookmark   April 28, 2011 at 1:13AM
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jellero

all my plants are infested and yes, it can drive a person nuts.i think the only way to get rid of the flies is to get the plants outside where natural predators can eat them up. you can sterilize the soil by putting the pots in a microwave after watering it but it's too late now for me. i am moving what plants i can into my garage now that it has warmed up but it's too early to put them outside.
i hung some fly paper and they caught thousands but that didn't touch the masses i must have in the soil. i also tried putting about 1" of pea sized gravel on top of the soil. don't have any peppermint tea so mixed some spearmint extract in water and applied to two plant's soil, we'll see. i think all my efforts have driven away my pet spiders.....
i'll check back here, hopefully there will be an answer.

    Bookmark   April 10, 2012 at 6:50PM
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donna_in_sask

I got fungus gnats in a bag of Costco soil a couple of years ago. That was the only time I ever had what I would call an infestation. I read that not a lot kill these things and a lot of what did is now banned for use. I've heard good things about mosquito dunks but have not used them.

    Bookmark   April 10, 2012 at 8:12PM
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savona(z2bBCCanada)

When I had an infestation with fungus gnats I found the best thing to use was Wilson's bulb and soil dust..but I doubt you can buy it any more.Small seedlings are the most likely to be killed by the larva..I hate the little pests!

    Bookmark   April 10, 2012 at 8:45PM
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nutsaboutflowers(2b/3a)

Forgive me if this has already been suggested. This thread is pretty long so I opted not to read it all =:) I've never had fungus gnats.

Did you try yellow sticky cards to capture the adults? They apparently like yellow.

For the soil, you could drench with insecticidal soap. Apparently works like a charm.

best of luck

    Bookmark   April 10, 2012 at 9:06PM
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don555(3a)

I use biological warfare. Like yellow stickies, sundew plants won't get rid of fungus gnats, but they reduce their numbers and the gnats are free-food for the sundews. I put a pot of sundews under my basement grow lights along with my other plants.

Every black spot used to be a fungus gnat before its insides were dissolved and digested by the sundew :)

A close-up of sticky sundew death for fungus gnats.

    Bookmark   April 13, 2012 at 6:11PM
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SnorkMaiden

I came across this thread while seeking a solution to a fungus gnat problem that resulted in the death of an indoor arrangement of succulents. After a move to a new home with better light conditions, a thorough cleaning of the original pot, new soil and new plants, the fungus gnats started up again and spread to all my houseplants and the seedlings I started for my garden.

After finding this thread, I tried spraying with peppermint tea (I didn't want to water because I was trying to let the soil dry out as much as possible). The flies seemed greatly disturbed by the spraying, but after several days of repeatedly spraying the population continued to grow.

I did a google search for peppermint bug control and found a recipe using 10 parts rubbing alcohol to one part peppermint oil and I just tried spraying it on the plants. My plants are now littered with tiny corpses, and it only took seconds to kill them all.

I'm reluctant to recommend this treatment to those who haven't had much luck with tea, as it remains to be seen whether the alcohol or peppermint oil will have any negative effects on the plants. I'll update after some time has passed. Fingers crossed!

    Bookmark   April 24, 2012 at 7:30PM
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don555(3a)

Snork, I wish you success but I fear the odds are stacked against you. By spraying the plants you are only getting a small fraction of the gnats. The big reserve is in the soil as eggs and larvae and the foliar spray doesn't touch that population. If you want to get rid of them, you really have to kill the larvae in the soil, otherwise you just kill off the flying gnats, and they resupply in a few days as new larvae mature. I've had some success with a dilute malathion drench in the soil, but it does emit a chemical odour for several days at least, which probably isn't great for a person either.

    Bookmark   April 25, 2012 at 2:29AM
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kioni(3)

I "believe" I've had success with a two part attack.
I heat my plant water to 50C, and make a mixture that is one part hydrogen peroxide and 3 parts water. For really large pots, I would place the pot in a large enough bowl/saucer to hold water, and add water to the bottom to come up 2 inches, then water from the top with more of the 50C hydrogen peroxide water. Supposedly the bubble action of the peroxide is enough to kill off the larvae near the surface, and the heat of the water does too. I would always find dead whitish larvae on the outside of the bottom of the larger pots from the bottom watering. This has to be done continually, with all plants, over a period of a time. My numbers began to decrease, then all disappeared. Now I see a few back again, but I've been making nursery purchases, and keeping in the house because it is too cool to keep outside (coleus, potato vine, begonias etc). I just keep up with warmer water (now at body temp, and a smaller percentage of hydro peroxide, about 1 part to 4). Apparently, herbs and plants that have scented leaves to not appreciate this treatement, but I have not had one houseplant or outside garden plant die from it.

I purchase the 3% mix from the local big box store, cheapest I can find if 1 litre/$2. Nearby reputable nursery purchases the 30% stuff (which would apparently eat the skin of your hand in seconds if applied! Yikes!) and apply a week solution to their plants for part of their bug control method. It bubbles as it sinks through the planting medium, and fluffs it up, sometimes too much, so the soil it puffed up like a muffin or cupcake would when done baking in the oven. So once I feel I've got the #'s of gnats under control, I weaken the mixture (1 to 4 or 5 water), then it doesn't foam up so much. I am now addicted to watering this way, especially the succulents in winter, gives them a drink but doesn't leave them wet for long, soil dries out faster. Summer they all get straight water.

I also operate some indoor worm bins, and one know that one for certain is a breeding ground for those pests, so I keep it wrapped in a bedsheet that I change with each feeding. I freeze the sheet with the flies trapped in it to kill them, then shake 'em out on the deck or in the tub (winter) and rinse them away and start over. But in the general area of the house, except for the odd couple I've noticed in the past 3 weeks (due to not being able to say no to taking home bedding plants because it's too cold for them to live long in the Canadian Tire greenhouse here!) I think I've got a good handle on them.

~kioni~

    Bookmark   May 6, 2012 at 11:27AM
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IContainerGardener

Thanks everyone for sharing these great tips. This is my first year container gardening and I think fungus gnats are killing my cherry tomato plant. Something I read about recently and just tried today, was watering the plant with nicotine water, but I like your suggestions better since I have cinnamon in my kitchen and I already use peroxide for household cleaning.

But if anyone wants to try the nicotine water, the post I read said to put the tobacco from 1 cigarette in 1 liter of water, soak overnight, water plants with it the next day and then water this way for 3 consecutive waterings, letting the soil dry our between waterings. I would share the link for the post, but I can't seem to find it again.

I also tried the peroxide for cilantro, catnip, sweet basil, and parsley seeds I am trying to grow into seedlings today because I saw the fungus gnats flying around the soil. I didn't dilute it with water though, so hopefully it wasn't too much for them.

Also, I just bought a peppermint plant on sale at a local greenhouse and I was wondering, do you think it would work to just put peppermint leaves in the soil?

Thanks again to everyone for the helpful tips.

    Bookmark   July 10, 2012 at 9:27PM
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chilliwin(EU DK 7)

It is an old thread but the problems of fungus gnats is never old. I haven't used peppermint yet. Before I did not know I have fungus gnat because I did not know what it was. A couple of guys here identified this insects then I have been trying to get more information about it. I do not like to start a knew subjects so I searched the forum and found this thread. So I took this opportunity for further discussion and help each other in this thread.

I read the opinions of using mosquito dunks and insecticide. Furthermore I googled for more information and found cinnamon to use against fungus gnats. Some of you already explained the positive result of using peppermint tea, it is very helpful information for me.

I am requesting your advice about these two means to get rid of fungus gnats - peppermint or cinnamon. I have cinnamon bark so I used it in two containers today. The result may know soon. I would like to know more information if you have.

    Bookmark   November 27, 2012 at 12:15PM
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marricgardens

I had an infestation of fungus gnats. I searched the web and found out that cinnamon works. Apparently it works because it is a fungicide and it kills the fungus that the gnats eat. All I know is that 3 days later-no more gnats! Now I always keep cinnamon around. Marg

    Bookmark   November 28, 2012 at 8:47AM
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marricgardens

I had an infestation of fungus gnats. I searched the web and found out that cinnamon works. Apparently it works because it is a fungicide and it kills the fungus that the gnats eat. I sprinkled on a layer of cinnamon to cover the entire soil and I also vaccumed up all the adults. By the next day there was a reduced no. of gnats and the day after that there were none! Now I always keep cinnamon around. Marg

    Bookmark   November 28, 2012 at 8:52AM
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