URGENT Question Tiny gnats in my soil.

Deebs

The Sentient Naturewalker
Staff member
Moderator
 

Capt. C

Saltwater Cowboy
Staff member
I found tiny gnats in my soil of my plants today. Googled it and they seem to be Fungal Gnats. The website says a 1:4 solution of peroxide should kill off the larvae. Does anyone know if this work and is safe?
I think @AlienAthena uses that method. Should be a few threads already posted on battling these pests. Unless you have them already yellow sticky paper is needed immediately.
 

Deebs

The Sentient Naturewalker
Staff member
Moderator
Do not over-water, and try to keep the relative humidity of your garden low, do not let the surface of your grow medium stay soggy.

Repression: Reducing surface moisture in your plants medium will slow fungus gnats reproductive cycle dramatically, the drier the better. Applying an anti-algae product around the bases of your plant will kill any growing green algae and reduce the food sources of growing maggots. Yellow sticky traps placed 2 inches from the base of your medium will snag a good chunk of departing adults.

Spray: Neem or insecticidal soap applied as a soil drench will kill eggs and larvae present in 1-3 applications. Any pesticide spray containing the fungal culture Bacillus thuringiensis var. israelensis (Bt-i) will successfully eradicate adult gnats. Apply soil drenches and spray simultaneously every 5-10 days.
 

Capt. C

Saltwater Cowboy
Staff member
Do not over-water, and try to keep the relative humidity of your garden low, do not let the surface of your grow medium stay soggy.

Repression: Reducing surface moisture in your plants medium will slow fungus gnats reproductive cycle dramatically, the drier the better. Applying an anti-algae product around the bases of your plant will kill any growing green algae and reduce the food sources of growing maggots. Yellow sticky traps placed 2 inches from the base of your medium will snag a good chunk of departing adults.

Spray: Neem or insecticidal soap applied as a soil drench will kill eggs and larvae present in 1-3 applications. Any pesticide spray containing the fungal culture Bacillus thuringiensis var. israelensis (Bt-i) will successfully eradicate adult gnats. Apply soil drenches and spray simultaneously every 5-10 days.
@Deebs was it you the other day saying that it was a good idea to let the BTi soak in water for 24 hrs before applying?
 

Capt. C

Saltwater Cowboy
Staff member
Not I, but I have heard many doing exactly that..
I am starting that method on this round as i have declared outright war on those little bastards. I did the Mosquito bits and DE at the top and bottom of the pots on the final transplant. I will continue to treat once a week with the BTi and yellow sticks as well. I am running 3 gallon pots of strait coco and hand water every morning. If i try to skip a day during heavy flowering points the pots simply get to dry. Wish i could keep the coco wetter actually as i get a better growth rate with heavy moisture in the pots.
 

HydroRed

3Thirteen Seeds
Staff member
I found tiny gnats in my soil of my plants today. Googled it and they seem to be Fungal Gnats. The website says a 1:4 solution of peroxide should kill off the larvae. Does anyone know if this work and is safe?

Sand as a top layer in your soil is a great option for suffocation like @EatPraySmoke suggests and a good first approach if you are trying to remain pesticide free. If you do apply the BT dont use any H2o2 with it. It will kill off any of the beneficials in the BT. If you use the H2o2 alone, your plants will actually perk up from the oxygen boost right after treatment. The only byproduct of the h2o2 itself is water.
 

Drynobbob

In Bloom
Increase air movement, add a fan, something, can't stress it enough. Hardens the plants up quicker and knocks down them pecker gnats. I spray my spinosad on if needed, it's a systemic I think, wait week apply again. If I want instant kill, I do the bonide pyrethrin stuff. I don't have to use bug juice indoor at all these days. I did give the two outdoor girls a bath or two for a fighting chance on varmints. I've never seen the ticks etc like they are this year
 

jpcyan2

In Bloom
Bt-i and Bt-k are only effective against the larval stages of fungus gnats. Great for soil dunks and watering-in. If gnats are the only issue, dont use as a spray or foliar.
I have a love hate relationship with Bacillus. Several great varieties for horticulture applications and several devastating varieties for myco projects.

The Spinosad is some good stuff too. I'm really diggin' the Captain Jack's Dead Bug myself. I'm using it indoor and outdoor.

Sometimes it takes a multi-pronged plan of attack. All the ideas here are effective alone. Used together.. dead gnats, good riddence.
 
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