I can't shake these fungus gnats...

[Natural]

I've been fighting them for about 15 days now! (right when I transplanted)

For the first few days I sprayed the plants/soil with neem oil and organic insecticide. Did nothing.

Then I went and bought 'desert sand' and covered my soil with it, in hopes of trapping the gnats and their eggs in the soil. No luck, they've seemed to make their way through a half inch layer of sand.

I cover the soil and plants once a day with neem oil/organic insecticide and still they're there.

I cleaned my cab out with water + bleach and sprayed 'raid' on my floor where the gnats usually are crawling around.

I'm out of ideas, please help!

 

[Bigmone357]

Get sticky flytraps hang em' in your grow area try that I use mosquito dunks (BT) biological warfare lol and the sticky fly traps.Gluck

 

[GMT]

let the top layer of soil dry out more inbetween waterings.
Wont get rid of em, but it drastically reduces their numbers

 

[2buds]

Look for the yellow sticky traps. I bought them online when I bought ladybugs but you may luck up at the stores. They fold open and have a grid on them, covered in a nice sticky glue that's real fun to stick your hand in or lean your head in to. The gnats love to stick to them. I also keep the no pest strips in the grow, the gnats don't seem to care much for them either. Wish you luck!

 

[hogwild]

let the top layer of soil dry out more inbetween waterings.
Wont get rid of em, but it drastically reduces their numbers

this is the best advice, fungus gnats are a major problem in my area and the only way to get rid of them is to create an environment that is unfriendly for them. If you have an oscillating fan turn it up to full power and put those tat strips everywhere, that will catch a lot of them, but in order to completely get rid of them you have to watch your watering closely and make sure you give the soil ample time to dry between waterings. These things suck, the larvae will eat the fine hairs on the plants roots, which will decrease your yield and cause further root rot, i HATE them!

 

[Guest]

I say do both but for sure hang the sly traps, if there too long just cut them into strips and hang em' on something. Becuase letting the top of the water dry won't kill the ones that have already formed

Anyone know what exactly forms fungus gnats, its a pretty strange concept, bugs from nothing

 

[Blackvelvet]

Its not the adult gnats you have to worry about but the larvae in the soil eating your roots. Drench the soil with bacillus bacteria. This is the ingredient in mosquito dunks for ponds, mosquito killer in bottles, and gnatrol, which is a product made for these applications. Going rate on a dunk is 1/4 to 5 gallons (3.8L) of water.

 

[twiztidbudsmoke]

dude seriously where do you get your soil i would kick the shit out of someone if I had little worms in my shit I dont know about you but I pay a pretty penny for soil, I would get a refund if I were you and start with a new soil that is hopefully steralized

 

[ngakpa]

the ladybirds / ladybugs will be out soon

I often find them on the fennel plants in my garden

they like to eat thrips - which are what I think you have

they are nigh on impossible to get rid of, but I suggest watering your plants from the base as much as possible

they do not like citronella (used sparingly in the air generally)

 

[Guest]

Theese pesky gnats are a difficult enemy. I had tried everything. I had no gnats 'till I bought some mushroom compost at a garden supply store. Nothing eliminated theese critters and they CAN affect your plants. Finally after reading way too much about the life cycle and sex habits of this miniscule enemy I discovered that freezing temperatures>0 degrees for three days kill them. Now I am happy. Freezing several hundred pounds of organic matter is easier than sticking it in the oven. Every soil, compost, manure and what not go to the freezer, 20 kilo's at a time. I had tried all the suggestions here and while catching and killing a few never got rid of the pests. Now after freezing all soil they ar gone. I am using organics and this may ruin timed release soil and fertilizer. Not 1 gnat in 3 grows.

 

[caljim]

Letting the top few inches of soil dry regularly is key to keeping fungas gnats away.

But if youve allready got them heres a couple options to get rid of them:

---Like stated above, let the top few inches of soild dry out well before watering again.

---Add a layer of diametacious earth to the top of your pots. When the gnats crawl thrlough it it cuts into their bodies and kills them

---Drench the soil with a diluted solution of neem oiL. Neem interferes with the gnats larve molting process. If they cant mature they cant produce more offspring.

Some more aggressive tactics:

--- Drench the soil with hydrogen peroxide at 3% in solution.
This will kill the gnat larve, but it will also wipe out any bennificial collonies in your medium and can burn root hairs if used at too high of a concentration.

---Gnatrol or Avid will get the job done. Be careful with these and be sure to read the directions, MSD Sheets and wear the appropriate protectice gear.

Finally a word about temprature. If you can keep your temps low or lower (low to mid seventies) you will slow the down their reproductive cycle, where higher temps can kick them into overdrive.

Good luck, hope that helps.

 

[Guest]

STEP 1: Put 1 tsp. of apple cider vinegar, fruit juice or wine in a small bowl of water near infested plants to trap and drown adult gnats.

STEP 2: Tempt adults to lay eggs away from plants by putting sprouting wheat grains in a container next to the plants. Bury or burn egg-laden sprouts after a few days and repeat until laying cycle is broken (8-20 days).

STEP 3: Remove 1/4 inch of topsoil and replace with diatomaceous earth (the skeletal remains of marine algae) to kill the soft-bodied larvae.

STEP 4: Use yellow sticky traps to lure and capture the gnats.

 

[vonforne]

1 inch of play sand and sticky traps. I had them last fall, bad. After I done that no gnats. Like Octo said I got mine from the mushroom compost. But growing organically you have to expect things like this.

 

[Sleepy]

expect 3 weeks to a month until they are gone.

you have to interrupt their life cycle.

kill them this week, add sticky traps to prevent more eggs from being laid...

repeat for two more weeks.

hang a no pest strip for a couple of weeks....

gnatrol works well, but watch your pH...

neem works, but you must be patient.

good luck.

now go kill some little fuggers!

 

[Guest]

The freezing sounds promising I will have to try that

 

[imnotcrazy]

GET MOSQUITO DUNKS: they have same active ingrident as Gnatrol (BTi) and after the first time I used it never saw fungus gnats again (but I also stopped using RW as a medium after that)

 

[MAUIWIZARD]

Take clear packing tape and tape over the top of your pots sticky side down and use sticky traps for the rest of them little bastards

 

[SneakySneaky]

heres my recipe, had a buddy gimme gnats, mites and thrips (nice friend eh?), and it was bad with gnats, product called That Stuff Plant Wash helped immensely it can be used up to the day of flower. i used TSPW with Organocide, sprayed my room with fox farm bug off, and put up a hot shot pest strip, after a week of spraying nothing lives, no lady bugs, beneficial insects, nothing, if beneficials cant live, pests cant either

ps, ive also killed gnats by putting a 1.5" deep layer of sand on the top of my soil plants, the larva gets cut up by the granules while trying to climb up outta the sand and most all die.

 

[TheHashAssassin]

aquabac, its a misquito larvacide, I used it once, and havent seen gnats/thrips since then. Enough said.

 

[Natural]

Sorry forgot to follow up on this thread!

I used neem oil, those sticky fly traps and covered my soil with sand. The problem seems to be fading away.
Before 20+ gnats would fly out of my cabinet when opened, now there is usually only 5 or so crawling around on the floor. They seem to be quickly dying out...

Thanks for all the suggestions!