Controlling Fungus Gnats Indoors in Soil.

[MensaBarbie]

Biological insecticide used to control whitefly, thrips, aphids, and many other soft-bodied insects in greenhouse and field crops. Based on the highly successful fungus, Beauveria bassiana, strain GHA, it controls the most troublesome crop pests – even resistant strains. Because of BotaniGard’s superior formulation, higher spore concentration, high viability and proven performance, it outperforms other Beauveria-containing products. When properly applied, BotaniGard’s insect control can equal or exceed that of chemical insecticides.
http://www.bioworksinc.com/products/shared/botanigard.pdf

 

[RB56]

Nice! Probably works really well as mulch too...

It does. Mesh also makes clean up after harvest easier. I used a layer of sand and then a layer of pea gravel for a few runs before I tried the mesh. Trying to separate the sand and gravel for re-use was time consuming, Now the mesh keeps soil and gravel apart. Gravel just pours off now, into a bucket to be rinsed before next use.

I know a lot of people see a thread on fungus gnats and have alternative killing solutions. The real point of this is to prevent the problem in the first place or at least limit it to the less protected beer cups. Fungus gnats are quite easy to kill, as long as you understand the life cycle. I've had 100% success with Gnatrol so stopped trying other killing techniques because 100% is good enough for me.

Preventing fungus gnats from establishing an infestation is better than anything that eliminates an infestation after you've identified it.

 

[GrowerGoneWild]

Great post I learned alot...

Just gotta add this.. FG, can hide just about everywhere, I was finding them in my dehuey, in moist corners, etc. Gnatrol is fine for the plants but I apply more agressive controls in areas away from my plants carbaryl, permethrin.

 

[razor ridge]

neem meal in your soil done deal

 

[Jhhnn]

It does. Mesh also makes clean up after harvest easier. I used a layer of sand and then a layer of pea gravel for a few runs before I tried the mesh. Trying to separate the sand and gravel for re-use was time consuming, Now the mesh keeps soil and gravel apart. Gravel just pours off now, into a bucket to be rinsed before next use.

I know a lot of people see a thread on fungus gnats and have alternative killing solutions. The real point of this is to prevent the problem in the first place or at least limit it to the less protected beer cups. Fungus gnats are quite easy to kill, as long as you understand the life cycle. I've had 100% success with Gnatrol so stopped trying other killing techniques because 100% is good enough for me.

Preventing fungus gnats from establishing an infestation is better than anything that eliminates an infestation after you've identified it.

I need to try your mesh/gravel technique. Thanks for that.

I def agree about gnatrol. Last cycle, I had the little bastids really bad, apparently from using recycled soil from a previous grow where they'd merely been a nuisance. They got a jump start on me, actually caused a problem w/ leaf necrosis that looked like calcium def. I just followed the directions, split the difference between the recommendation for light & heavy infestations, which is 1 Tbsp/gal. 3 applications a week apart annihilated 'em. I doubt that a neutron bomb would have been more effective.

Good shit, Maynard. Really good shit. $50 for 500g, Amazon Prime. That's ~1 qt or 1 liter.

 

[RB56]

I switched to 70/30 coconut coir/perlite about 6 months ago and continued the mesh and pea gravel. The gnat population has exploded outdoors because of high temps and humidity but for the first time in 3 years of growing, summer is almost gone and I have yet to have ANY infestations. 2 adults have showed up on sticky traps. Don't know if they don't like this medium as much as soil but no Gnatrol, dunks or poisons and gnat free.

 

[Granger2]

Gnatrol and other BTi preps, if fresh, work well, but if you want the beauvaria, use the liquid so your not breathing dust during mixing. Good luck. -granger

 

[RB56]

Gnatrol and other BTi preps, if fresh, work well, but if you want the beauvaria, use the liquid so your not breathing dust during mixing. Good luck. -granger

The point of this thread is that preventative measures can avoid the problem in the first place. Honestly, your post is strangely random. Like a robot sees Gnatrol and auto-posts

 

[buzzmobile]

The point of this thread is that preventative measures can avoid the problem in the first place. Honestly, your post is strangely random. Like a robot sees Gnatrol and auto-posts

Mosquito Bits, the granular form of (Bt i), are an excellent preventative. Sprinkle them over soil surface of freshly potted plants, newly stuck clones, or mix them into a soil recipe. Fungus gnats are ubiquitous in grow rooms and Mosquito Bits and Gnatrol have a place in preventing them from becoming an infestation.

 

[RB56]

Mosquito Bits, the granular form of (Bt i), are an excellent preventative. Sprinkle them over soil surface of freshly potted plants, newly stuck clones, or mix them into a soil recipe. Fungus gnats are ubiquitous in grow rooms and Mosquito Bits and Gnatrol have a place in preventing them from becoming an infestation.

May be, but I reuse my medium and separating the spent corn kernels is a PITA. A preventative that doesn't use chemicals or biological agents is far superior As is often the case, sound practices avoid the need for band-aids.

 

[friendly530]

you can use sand on the top of the plants and i also agree gnatrol and sticky traps work well

 

[RB56]

I'm sure the usual suspects will stop in and explain how they kill fungus gnats (I've used Gnatrol with good results) but the point of this thread is how to avoid them in the first place. Simple steps in my first post.

Now that we've hit our first frosts of the year, I can report that I made it through the gnat season with zero infestations. This is the first time in several years of growing that I haven't had to kill an infestation. Got a few on the yellow sticky traps but they never established a breeding cycle.

Now back to OT favorite FG killing approaches ...

 

[mistymountain]

For prevention I keep away from using any soil that is rich in moss and make the 1-2" top layer of a mix of perlite and vermiculite.
For treatment I've used a spray of hydrogen peroxide with regular water, it kills (burns) the gnats and larvae and can be used up until harvest date with no ill effect to the plants or the smoker and is inexpensive. Just make sure to let the plants dry out before the dark period, so lots of ventilation and air extraction is the way to go.

 

[hayday]

bookin this thread.
last year I had a terrible problem with these heartless little creatures.
Bleach in the P-traps might help some . seems to be where they start.

 

[SoulMachete]

Tanlin...will wipe out an infestation fast. Also let them pots dry out between waterings. And always hang sticky traps whether you have a problem or not. Peace

 

[methias]

Fungus gnats DO come in store bought soil. Crumble mosquito dunks and sprinkle on soil=problem solved

I powder mosquito dunks (mortar and pestle) then I add some as I mix my "Foxfarm Ocean" / "Palm and cactus" mix. I wanted to leave them no safe haven to reproduce (top or bottom) in the pots and cups.
2 parts Foxfarm
1 part palm and cactus mix.

neem meal in your soil done deal

Next I toss in some Neem seed meal and mix it all together in a bucket.
I sprinkle on just a touch of water (if the mix is really dry) and close the bucket.

I finally got this mix in everything in my clone / mom box and the gnat population seemed to be dropping so I wanted to know how it works.

Test time.
Yesterday I took pics of my yellow sticky traps after putting in brand new ones.

These set right over the soil like a little tent.
Many a gnats first foray into the world were suddenly and abruptly terminated.

Today, 24 hours later and I see 4 little bitches stuck on the traps.


And

From below.
A little dirt where its edge touched the soil, but looking good.

I'll see how it goes through the week but I'm stoked.

That deserves a vape

Vape on.

 

[Flowerman]

Nice thread, also using Beneficial Nematodes in ur mix will help keep them under control, never had a real problem until this year with them, and didn't catch it until their little larvae asses ate the roots and killed some seeds I was germinating. Was thinking about adding sand on top as a layer of defense, but so far, yellow sticky traps, and the nematodes are keeping it under control, still have a few flying, but it's nothing to write home about. But will one day try the sand to see if that really helps or not.

 

[Weezard]

The sand thing is a PIA.
Just put dryer sheets on the soil surface.
They shield the soil from egg laying and hatching.
But the big deal is, they actually REPEL the flyers.


Cleared my heavy infestation 11 years ago.
I change them out for fresh ones every 30 days or so.
They are inexpensive, harmless to humans and pets, and very effective.
And before you ask, they do not affect the scent, or flavor of my meds.
I use Kirkland "lightly scented" because Bounce sheets reek and might affect scent.

 

[GMT]

Quark nailed it. Stop over watering, no more f.n.
Of cause if you encounter the Borg you have to over water, but otherwise, dry your soil out.

 

[RB56]

This is still working flawlessly for me in coir. Used to have at least one major infestation per year, haven't had one since I started doing this. Just want to add another tip. After a few cycles of use, the fiberglass mesh can get warped and distorted. Take a stack of the same sized pieces and drop them into a pot of boiling water for a few minutes. Fish them out and put them between two flat surfaces with a little weight added. As soon as they cool, they are back to flat and like new. I've been using the same pieces of mesh since I started using this technique. Same pea gravel too. Virtually no added costs, once you get set up.