WTF flies?

Hey potheads! I have a bit of a problem with my grow operation. I recently brought some plants from outside into my grow area, and now i have these tiny flies everywhere! I think they are fungus flies, but i cant be sure. I don't want to use anything harsh to kill them( i try to keep things organic) The flies dont seem to be hurting them much,but i just dont know!? What should be done about them. I heard a layer of sand would work. Any suggestions would be appreciated! Thx!!

STOP watering.
Raw potato slice(es) ON the soil surface. Leave a while. Lift and look. Fungus gnat larva should be in the potato IF you have them. Discard infested slice, replace. Repeat until slice comes up clean two times in a row, Gnats gone. 5 day life span. I flush infested potatoes down the turd-lette.
Result of not allowing soil to dry out enough between waterings.

The sand, I've read, works too, but I'd do the tater thing first, then the other?

Thanks mrfishy! I will try this technique right away. I should wait until the soil is completely dry until i water then? I water usually when the pot is not heavy. I hope it works!Thx again!!!!

Ask your local grow shop for yellow sticky traps... the fungus gnats are attracted to them like the DEA is attracted to shitting on patients rights.



they are very smart and work quite well.

MrFishy said:

STOP watering.
Raw potato slice(es) ON the soil surface. Leave a while. Lift and look. Fungus gnat larva should be in the potato IF you have them. Discard infested slice, replace. Repeat until slice comes up clean two times in a row, Gnats gone. 5 day life span. I flush infested potatoes down the turd-lette.
Result of not allowing soil to dry out enough between waterings.

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This is a great low-cost, low-tech, all natural remedy to those annoying little bastards. +REP for you Fishy!

Re: dry soil . . . use common sense as to how long you can safely wait to water. The object is to dry it out, from the top down, as deeply as is reasonable. Fungus gnats have a 5 day lifespan. They deposit eggs in moist soil.
Logic would dictate that letting the first 2-3 inches dry out for six days would be minimum for maximum effect?

Personally, I sprinkle some DE (food grade Diatomecious Earth) on the surface of the soil a day after I finally do water when dealing with these little buggers. I've never had a major gnat outbreak, so can't swear that this is a method for those with major gnat infestation.

Hey, thats sounds logical! I don't have a major infestation yet and hopefully they will be done with soon. I have some DE too. Thanks mrfishy and everyone else! You guys are the best!

I just wanted to say that I call them all what-the-fuck!-flies, too.

I'm with GT on the yellow sticky traps. Nothing works as well.

Yellow Ribbon Trap, 50´ - Worm's Way

^^^ This roll is actually quite large and it could last for years. You only need a small square per pot or a couple pots at that. Slice the end of a straw in half and insert sticky trap and stake into container.

Sand will get crusty and eventually have to be removed. DE will get watered into the soil and provide lots of silica to the roots but it isn't effective (gnats) unless it's dry. Potato slices will not completely eliminate the pest.

Seamaiden said:

I just wanted to say that I call them all what-the-fuck!-flies, too.

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Lol,they are annoy things! Do they cause any harm to the crop tho? Damnit, I just ordered some nutes from wormways, but i didnt get the tape! It's to late i'll have to get it with my next order. Good ideas all around,thx!!

Left unchecked, the larva feed on your plants' roots.

vacume the fuckers up

Tried the vacuum once. Picked up more dirt than anything. It did bring their numbers down though.

Here's what I used to rid the gnats. Sprayed three times, 3 or 4 days apart. Kept the Pic Stick sideways on top of the dirt.

Haven't seen em since. Except for the dead ones. Good ridance.

smokymcdutch said:

Lol,they are annoy things! Do they cause any harm to the crop tho? Damnit, I just ordered some nutes from wormways, but i didnt get the tape! It's to late i'll have to get it with my next order. Good ideas all around,thx!!

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The flies I get are all over my tea (I think because it's got a bit of malt extract in it from the wort we made last Sunday) more than my plants, though bugs seem to be attracted to the fluoro lights and I get a lot of bugs up in them. But, yes, I do believe the gnats indoor growers get are harmful, can't tell you more until I go read more, and I just toked up some scissor hash. (we need a guy smokin' a pipe)

You can buy those sticky traps just about anywhere I think. If you can't find those, maybe try some flypaper til you get some traps, eh?

I hate gnats, usually get them from shitty soil. I use a layer of sand instead of a potato. The yellow sticky tape and sand combined takes me 2-3 days to get rid of the pest.

Mosquito dunks work quite well. I like to let the soil dry out as much as I can stand and then break up about 1/4 to 1/2 of a dunk on the top of the soil and water thouroughly. to the point where there is a little standing water. It is a Biological agent (bacteria) that infects larva and kills them.

The best approach I have found for fungus gnats is a shotgun approach. First I like to try and keep them out by putting a filter on intake. panty hose, hepa, etc.. next make your garden inhospitable with neem oil. I have had neem oil and hot lights burn plants so I like to apply it just before lights out a couple times a week. Then use lots of sticky traps. I like the 3x5 white fly traps. Then use the dunks. Lastly you can use sand on top of the soil so the adults cant lay eggs. ( I think sand is a pain so I only use when infestation is severe.) then some potatos to get any larva that were not killed by the dunks. this way you are combating them on every life stage. keep adults out with filters. keep adults from settling with neem. Keep adults from laying eggs with sand. Keep larva from surviving with dunks and catch any strays with potatos.

FYI. The dunks do contain small amounts of pesticide yet are certified for organic production, go figure. I go all organic with the dunks being the only gray area. gnats can really harm your plants. I can really notice how much slower they grow and how much less they drink when those bastards are eating the roots. You can get dunks anywhere that sells pond supplies.

hope this helps kill lots of gnats out there!
Cheers.