HELP! Fungus gnats

[Kinncreek]

I suddenly have a lot of fungus gnats. I was wondering if I could spray Neem oil on the plant when it’s in the flowering stage?

[aDamBuster]

I had the same. I sprayed neem oil on the top layer of soil and around the plants, and laid some sticky yellow pads around. Seemed to do the trick.

[Cali]

Why would you want to spray Neem oil on the plant for fungus gnats? The gnats are not on the plant they are FUNGUS gnats. You need to put Neem meal on the soil or spray the soil with the neem tea. Or you can cover the top of your soil with Diatomaceous earth (foodgrade) that should take care of them.

[Ckbrew]

Last time I had these pests I used diatomaceous earth mixed with dry pro-mix. Spread on top of the pot about 1cm deep. Also this is a sign of over saturation of grow media. Hold the water until they dry out. When you do water, just pour in one spot. The dry pro-mix tends to float on the water until it is absorbed into the media.

[ChadWestport]

I wouldn't spray anything on the plant, this is really an issue of moist top layer in your soil. This is where they and the eggs will be dwelling. CKbrew has a good suggestion with the diatomaceous earth, which is water soluble, so don't apply it before or right after you water. Another way to try and manage fungus gnats is by letting the top layer of the soil get a little dry in between waterings. The wet top layer is their preferred environment.

I'm not sure what sort of pot you are using, but some people have even cone a few bottom feedings instead of watering in the top. This will still get water to the root zone, but it also keeps the top layer dry. It's not something I recommend for the whole life of the plant, the would be an ebb & flow table, but doing it a few times to manage the gnats shouldn't hurt you any.

[Rwise]

Do not use neem on buds! A fan will help.

[Kinncreek]

Thank you all for your advice and suggestions. Now I can hopefully at least cut the population of gnats
down.

[Geofite]

I used mosquito dunks to get rid of fungus gnat infestation last year in my tent. "There is a naturally occurring soil bacterium called Bacillus thuringiensis subspecies Israelensis (BTI) that kills the larvae of fungus gnats, mosquitoes and black flies . When BTI is eaten by these larvae toxins are released into their gut which causes the larvae to stop eating. Without food the larvae die. This interrupts the life cycle of these pests and the population then dies off.

BTI is not harmful to humans, birds, fish or mammals. Deemed Fit For Organic production by the USEPA in accordance with the USDA's National Organic Program.

Floating a dunk in your watering container will condition the water with Bacillus thuringiensis subspecies Israelensis (BTI) that can be used as a soil drench to get rid of fungus gnat larvae. Each dunk will condition water for several refills." https://www.repotme.com/products/mosquito-dunks

[Cali]

Geofite tjat is exactly how Neem works. It also makes them sterile (adults) so they can’t reproduce, and so much more plus it’s a great fertilizer if you will. Helps keep the nitrogen in the soil.

[Geofite]

Geofite tjat is exactly how Neem works. It also makes them sterile (adults) so they can’t reproduce, and so much more plus it’s a great fertilizer if you will. Helps keep the nitrogen in the soil.

I don't like the smell of neem oil, especially in my house. Mosquito dunks have no smell at all.