Gnat Control

del66666

Well-Known Member
Hi Del,

So far so good w/the mosquito dunk water, haven't seen any gnats today. TY for the aspirin idea, wonder how well it would work for in-ground outdoor applications?.

Seems like it wouldn't hurt as a preventative measure.

Cheers!
the aspirin idea was first used on outdoor flowers, veg etc....all plants sprayed with and watered remained healthy and were more productive....i use neem a round 2-3 weeks into flowering so i dont get any attacks at the most important time......been using aspirin for a few months and things are looking good.
 

personified

Active Member
Never heard of the cinnimon method will remeber and try it.

A thin layer of Coffe Grounds on top of the soil works for me they do not like the acidity.
 

Sunbiz1

Well-Known Member
Never heard of the cinnimon method will remeber and try it.

A thin layer of Coffe Grounds on top of the soil works for me they do not like the acidity.
Coffee grounds are good for azaleas, blueberries, and other acid loving plants...not so great for cannabis. I ditched the idea in favor of cinnamon for this reason.
 

Sunbiz1

Well-Known Member
the aspirin idea was first used on outdoor flowers, veg etc....all plants sprayed with and watered remained healthy and were more productive....i use neem a round 2-3 weeks into flowering so i dont get any attacks at the most important time......been using aspirin for a few months and things are looking good.
Clicks non-existent like button...ty again!
 

Scoobydo

Member
I have pulverized egg shell in my soil mix ( powdered in a blender ) works like DE. I also make an insectacidle soap that takes care of an outbreak. I'm oldschool like Jerry Baker lol.

2 T Garlic juice
1 T Habenaro juice
2 T Dawn dish soap
1 gallon water

Can be used as a spray on non flowering or a drench when in bloom
 

NickNasty

Well-Known Member
Captain Jacks Deadbug brew will get rid of Gnats, Spider mites, Thrips, Caterpillars and numerous other pests and it's organic. Stuff works wonders with one spray you can get rid of them all.
 
TY for this and to the poster you quoted as well, that clears up a few myths.

Question for you/all.

What is the best top dressing to use for prevention?. Gnats LOVE the worm castings I've been using, I'm tempted to use coffee grounds and simply scrape them off when I bring them back in. Grounds are great 4/blueberries and azaleas, but most cannabis strains don't care for acid.
i use perlite to get effect use about a 1/2 inch on top of the soil stops the buggers getting down to lay there eggs, only thing is u have to water from the bottom to stop mold growing on the perlite, takes a little long but i dont mind
 

kentuckyboy

Well-Known Member
I had a gnat problem last grow, and I wasn't prepared for how fast gnats can go from a couple to seeing them flying everywhere. Even getting out of the grow room into the rest of your house which set off the alarm for me. I used neem oil with water to drench the soil. I was flowering, so I didn't spray the plant itself. I would've if I was still in veg stage. I also put a layer of fish tank rock over the dirt to keep the gnats that are flying around from being able to lay more eggs. I think sand is more ideal though, but the rock and neem oil worked for me. I also used mosquito dunks too.
 

Nullis

Moderator
The best way to prevent and get rid of gnats is with biological controls. Bti/Mosquito Dunks is a bio-control, and it does work fairly well for helping get rid of gnats but is better applied before you have any in the first place.

If you have a bad infestation you need to take multiple steps to eradicate them. Predator mites are the single best solution I have found. You can spray anything you want, drench your soil with neem oil, etc. and it will only work if you keep applying the stuff. You'll probably never completely eradicate them this way, and once you stop your gnats are just going to bounce back.

Predator mites like the Hypoaspis sp. are micro-arthropods about a millimeter or two large. They eat fungus gnat eggs, pupae and small larvae, as well as over a hundred other species of soil-dwelling pests. They play an important role in the soil food web essentially turning the gnats into fertilizer, shredding organic matter, shuttling and dispersing microbes. You can use them along with Bti and beneficial nematodes, although the mites may eat some of the nematodes.
 

Sunbiz1

Well-Known Member
The best way to prevent and get rid of gnats is with biological controls. Bti/Mosquito Dunks is a bio-control, and it does work fairly well for helping get rid of gnats but is better applied before you have any in the first place.

If you have a bad infestation you need to take multiple steps to eradicate them. Predator mites are the single best solution I have found. You can spray anything you want, drench your soil with neem oil, etc. and it will only work if you keep applying the stuff. You'll probably never completely eradicate them this way, and once you stop your gnats are just going to bounce back.

Predator mites like the Hypoaspis sp. are micro-arthropods about a millimeter or two large. They eat fungus gnat eggs, pupae and small larvae, as well as over a hundred other species of soil-dwelling pests. They play an important role in the soil food web essentially turning the gnats into fertilizer, shredding organic matter, shuttling and dispersing microbes. You can use them along with Bti and beneficial nematodes, although the mites may eat some of the nematodes.
That's exactly what I just started, watering w/Bti before I see anything b/c I *know there are unhatched larvae in at least one container. Problem is I don't know which one, so I'm watering them all.
 

Sunbiz1

Well-Known Member
Hi all,

I needed to dig up this old gem thread b/c I've tried everything and stopped the larvae hatching...but am unable to get rid of the juveniles and young adults. I keep eyeing an old bottle of pesticide in the basement, which I have never tried and is a last resort b/c I don't even know if I can flush it out afterwards. These 2 ladies are in early flower, over 4 feet tall and in 5 gals.

If I were to take these plants into the backyard for a few days, is there anything organic I can use with water that will cause them to go elsewhere?.

TY!
 

Sunbiz1

Well-Known Member
The best way to prevent and get rid of gnats is with biological controls. Bti/Mosquito Dunks is a bio-control, and it does work fairly well for helping get rid of gnats but is better applied before you have any in the first place.

If you have a bad infestation you need to take multiple steps to eradicate them. Predator mites are the single best solution I have found. You can spray anything you want, drench your soil with neem oil, etc. and it will only work if you keep applying the stuff. You'll probably never completely eradicate them this way, and once you stop your gnats are just going to bounce back.

Predator mites like the Hypoaspis sp. are micro-arthropods about a millimeter or two large. They eat fungus gnat eggs, pupae and small larvae, as well as over a hundred other species of soil-dwelling pests. They play an important role in the soil food web essentially turning the gnats into fertilizer, shredding organic matter, shuttling and dispersing microbes. You can use them along with Bti and beneficial nematodes, although the mites may eat some of the nematodes.
These are difficult to find, would have to order online.
 

Nullis

Moderator
Grow shops can order them for you, possibly even a Home Depot. I know certain Lowes or HD locations carry beneficial nematodes, which also attack fungus gnat larvae (only problem with them is they can't be seen without a microscope).

Do you have yellow sticky traps up? It's good to use both the hanging kind up high in your grow room, and also the kind that go on sticks that you put right into the soil. Vacuuming up the adults can also help. Water simultaneously and suck them up with the vacuum hose as they try to fly away, as many as you can. If you're going to use any kind of pesticide just use pyrethrins, which are botanically derived and break down very rapidly. You really need to attack both the adults and the eggs/larvae with Bti or another bio-control to bring control to the situation. Apply the Bti every other week.
 

NickNasty

Well-Known Member
Captain Jacks Dead Bug Brew will work for gnats and it is organic. Also I just had a bad outbreak of aphids which really hurt my plants and ended up trying this guys products mainly to boost my plants health but it also got rid of gnats. Here is a link to info about the packs https://www.thcfarmer.com/community/forums/capulators-beneficials.179/ and a link to where he sells them http://www.ebay.com/itm/for-the-farm-only-/230761890387 They are basically very high concentrations of a wide range of beneficials. Anyways check them out even if you don't use it for your gnat problem.
 

Sunbiz1

Well-Known Member
Captain Jacks Dead Bug Brew will work for gnats and it is organic. Also I just had a bad outbreak of aphids which really hurt my plants and ended up trying this guys products mainly to boost my plants health but it also got rid of gnats. Here is a link to info about the packs https://www.thcfarmer.com/community/forums/capulators-beneficials.179/ and a link to where he sells them http://www.ebay.com/itm/for-the-farm-only-/230761890387 They are basically very high concentrations of a wide range of beneficials. Anyways check them out even if you don't use it for your gnat problem.
TY,

Fortunately fungus gnats are not as serious as aphids/white flies etc. The only effect I have noticed in 2 years of dealing with them are stunted growth for new plants.

Why not simply take the whole plant outside and remove it from the 5 gal. Then I'll hose the whole root ball and re-plant back into fresh soil previously treated with Bti.
 

Kalyx

Active Member
Hey guys... Not trying to be base but.....this many posts and nobody tells the guy to hold back on watering. Water less often or less volume if you must water on a schedule instead of waiting patiently till your plant is light (there's more water in there than you think if you have LOTS of gnats they are a sign of overwatering IMO).

Also, the flyers will lay up to 200 eggs per day so hang those Yellow TRAPS and watch your arm hair! Aim your fans at the walls, gnats will be sucked in and splatted on the wall.

Another thing is don't buy mixes (anything in a bag) that has been stored outdoors for ANY period of time. IMO this is what leads to gnat orgies. Don't necessarily diss the mix itself, it may have just been stored where gnats can get to it.

Azatrol is the best "cure in a bottle" I've heard mentioned. Go gnats is great too, any burning from it was probably an over application and it smells great (gnatrol was prertty foul I recall). Also, there are many sub-species of Bt (and they all get different bugs) so pay attention when shopping.

Sometimes it's more cultural practices, especially persisting issues. Examine your watering if the bottle cures can't stop em!:cry:
 

MG Canna

Active Member
I have used play sand for the last 2.5 years and I haven't had a gnat since then. All you need to do is put a 2 inch layer of sand on top of the soil and its now 100% impossible for the gnats to lay their eggs. Takes about two weeks to get rid of all of them. Sand is $3 a bag. I throw out the sand when I transplant. Some dirt will get to the top but it's not enough for the gnats to lay eggs in because it dries out in between watering. I've been doing this for a while with 100% success. Be careful when pouring water onto the sand. You can dig a hole through the sand easily and get lots of dirt on top. Best thing to do is place a small bowl on top of the sand and poor the water into the bowl. This displaces the water and is an easy fix. I would never put any pesticide into the soil and I would never use a spray on the plants after the first week of bud. This technique stops all bugs from invading your soil and it's 100% safe.

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