Fungus Gnats

[Tadu]

Just wanted to tell the tale of my encounter with these dreaded beasts. Last grow in another country had them and hoped I had left them behind, new country, new pots, new soil, but sadly a house plant from old house that clearly had some larvae. Well 4 weeks into flowering and they are emerging at an alarming rate. Went online and after hours of research I decided to go control and see what happens, bought a 20kg bag of silicate sand and put 3-4cm on top of soil in every pot including the guilty hoise plant. As well I have been killing adults with sticky traps and by hand, ught they seem to leave a slime skid mark! After a week I think the combination has worked, no new adults are emerging and the plants seem to be a bit happier, not sure if this is the best solution, but that late into flowering did not want to go chemical.

 

[Heygurlll]

Just wanted to tell the tale of my encounter with these dreaded beasts. Last grow in another country had them and hoped I had left them behind, new country, new pots, new soil, but sadly a house plant from old house that clearly had some larvae. Well 4 weeks into flowering and they are emerging at an alarming rate. Went online and after hours of research I decided to go control and see what happens, bought a 20kg bag of silicate sand and put 3-4cm on top of soil in every pot including the guilty hoise plant. As well I have been killing adults with sticky traps and by hand, ught they seem to leave a slime skid mark! After a week I think the combination has worked, no new adults are emerging and the plants seem to be a bit happier, not sure if this is the best solution, but that late into flowering did not want to go chemical.

fungus gnats are easy to get and to get rid of. you overwater,which is what will begin the FG outbreak (well you could be using too large a pot and then the one to blame is the pot.)

things that work....
fan directly on pot, emphasis on wet/DRY cycle. no pest strips can help but are not always recommended. sometimes larva and eggs survive even 3 week treatment, but usually works within 2-3 weeks.

diluted 3% h202 and proper wet dry cycle. kills everything but roots (which get an o2 boost) in the soil. everything (in ~5-7 days). so if you are growing organic or care about the micro-organisms, avoid this.

silicate sand/diatomaceous earth. cant say much bad bout DE.


I cant think of anyone who buys chemicals for fungus gnats..... its so simple to fix. and when transplanting, if you expose the roots and give a 1% h202 soak, you can kill all FG eggs/inert mold spores/root aphids/etc.
btw, the eggs often come in the soil anyways.....

 

[Doobius1]

Mosquito dunks. Google it. Buy em on Amazon. Bust them up into a powder and sprinkle on the top of every plant in your house.
Its not overwatering that cause gnats. Might enable them to start their cycle. They need damp organic soil to thrive but so does cannabis. You have to water your plants. The larvae come in most organic compost based soils. Just treat every new bag as it comes into your house. Sticky traps and covering the top with sand dont get rid of them long term

 

[Cpappa27]

Im Having the same problem now. Diatomaceous earth, gnatrol, Mosquito bits, and yellow stickies for the adults and they are under control. The fliers don't really do much but annoy you. Don't leave standing water in the drain trays.

 

[Heygurlll]

Mosquito dunks. Google it. Buy em on Amazon. Bust them up into a powder and sprinkle on the top of every plant in your house.
Its not overwatering that cause gnats. Might enable them to start their cycle. They need damp organic soil to thrive but so does cannabis. You have to water your plants. The larvae come in most organic compost based soils. Just treat every new bag as it comes into your house. Sticky traps and covering the top with sand dont get rid of them long term

thats why i was saying overwatering.... if they never successfully start their life cycle then they never become a problem. they need very moist soil at 75F for ~8-16 days to really set in full scale (3 to hatch, 10 to pupate, 4 more before adults start to mate).
you usually wont get them if your plants are drooping from thirst every 5-6 days, which they will if watered properly.
Its only the larvae that matter (to me) anyways. they really are nothing if a proper wet/dry cycle can prevent AND treat them. They are a weak species that relies mainly on mass procreation to avoid extinction from the planet, i mean come on, they have like 0 adaptability.


here, read these if you want to know about fungus gnats, they're the first two google results.
http://www.ext.colostate.edu/pubs/insect/05584.html
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7448.html

 

[Heygurlll]

Sticky traps and covering the top with sand dont get rid of them long term

Just now read that line. I now realise I've wasted my time on you. Show me a case of sand not fixing this within 2.5 weeks? The wet dry cycle is kind of ridiculous because you often have to water at the best time for the gnats.... but please, explain how sand can fail to kill them.... smh

 

[Doobius1]

Ive read posts on this very site about gnats burying through the sand and what a bitch it is to water with sand on top of your plant chokin out your roots. Im not playin the dick waving game with you. Dunks worked for me and many others.
Play in your sandbox all fuckin day for all I care.

 

[ImaFarmer]

only one o in tampons

 

[DutchHaze]

Mosquito dunks. Google it. Buy em on Amazon. Bust them up into a powder and sprinkle on the top of every plant in your house.
Its not overwatering that cause gnats. Might enable them to start their cycle. They need damp organic soil to thrive but so does cannabis. You have to water your plants. The larvae come in most organic compost based soils. Just treat every new bag as it comes into your house. Sticky traps and covering the top with sand dont get rid of them long term

How do I treat a new bag of soil? I feel like all my bug problems come from the bag of soil. Can mites come in the soil too or just gnats?

 

[Doobius1]

https://www.icmag.com/ic/showthread.php?t=142461

The main post I learned about this from was on icmag through a google search.
Dunks are supposed to be bacteria and we can use them in areas like ditches, ponds etc where the water ends up in our drinking water. 1 dunk treats like 10000 gallons so I would suggest just sprinking some powdered dunks in with the new
soil. As it gets watered, the dunks become active. Dry out, they are fine until next watering

 

[Doobius1]

only one o in tampons

Not according to Frank Zappa

Well the toilet went crazy, yesterday afternoon
The plumber he says 'never flush a tampoon'
This great information cost me half a weeks pay
And the toilet blew up, later on the next day

 

[SnapsProvolone]

You positive the pest in question is a fungus gnat? Sometimes winged root aphids are mistaken for fungus gnats.

Aphid wings are longer than the body, extending behind the ass. Look for the telltale aphid "dual exhaust" nubs...

 

[Flash63]

I had gnat problems in my coco.....started using sm-90.@ 5ml per gallon .....Have not seen a gnat for over a year now...there are many ways to skin a cat..

 

[Doobius1]

I need a Snickers bar.
Sometimes I get a grumpy when Im hungry

 

[Tadu]

Let us all just get along, I feel bad for posting, I am too close to harvest to try dunks for the first time, just wanted a simple method, and I agree I overwatered, the holidays and being away for a day or two made me do it!

 

[a senile fungus]

Let us all just get along, I feel bad for posting, I am too close to harvest to try dunks for the first time, just wanted a simple method, and I agree I overwatered, the holidays and being away for a day or two made me do it!

Mosquito dunks are nontoxic, and can be used at any time... But they do take a couple weeks to work so if used now it may not be effective till after your harvest.

For now be careful of overwatering, and the silica and or diatomaceous earth will help. Sticky traps for physically trapping them is crude but will work to reduce numbers of flyers, but as stated above, their life cycle needs to be disrupted.

What kind of soil are you using?

If organic, or you like organic solutions, then next time you mix your soil make sure to add neem meal, crab shell meal, and mosquito dunks and those little flying creatures will be a thing of the past.

 

[BigTexan]

if you need an immediate temporary fix until they are completely gone go get coarse silica sand (cement sand) spread about an 1/8 inch of sand on top of your pots it will prevent them from laying eggs and any eggs that hatch and travel through the sand will dry them out and kill them.

 

[Heygurlll]

then next time you mix your soil make sure to add neem meal, crab shell meal, and mosquito dunks and those little flying creatures will be a thing of the past.

YES! and 90%of other critters.
Honestly, i'd recommend this even if you don't like organic.

I'm considering adding lavender oil to the preventative pest control list. Penny for your thoughts?

 

[a senile fungus]

YES! and 90%of other critters.
Honestly, i'd recommend this even if you don't like organic.

I'm considering adding lavender oil to the preventative pest control list. Penny for your thoughts?

I've never used lavender but I've heard good things. Do you intend it as a foliar application?

I do have cilantro and garlic and sage in my outdoor garden in case of emergency, but I've never had to use them as pesticides. My outdoor cannabis plants always have bugs all over them, but never any damage to the leaves or anything bad at all.

I've had powdery mildew on my outdoor plants before but 1 part of fat free milk to 9 parts of bottled water sprayed liberally onto whole plant fixed that right up...

I'm of the mindset that healthy, living soil and healthy plants is the biggest step towards pest prevention.

I think of it this way, I work in a hospital and I'm around very sick people all day. I've been exposed to the flu hundreds of times this season, but I've avoided illness by being proactive about my health and cleanliness. I'm less susceptible to illness if my immunities are strong. I feel this is very similar for plants, which is why I like to provide my soil and plants with all they need.

Healthy plants can fight off pests and disease.

Hopefully they can anyways.

 

[Heygurlll]

I've never used lavender but I've heard good things. Do you intend it as a foliar application?

I do have cilantro and garlic and sage in my outdoor garden in case of emergency, but I've never had to use them as pesticides. My outdoor cannabis plants always have bugs all over them, but never any damage to the leaves or anything bad at all.

I've had powdery mildew on my outdoor plants before but 1 part of fat free milk to 9 parts of bottled water sprayed liberally onto whole plant fixed that right up...

I'm of the mindset that healthy, living soil and healthy plants is the biggest step towards pest prevention.

I think of it this way, I work in a hospital and I'm around very sick people all day. I've been exposed to the flu hundreds of times this season, but I've avoided illness by being proactive about my health and cleanliness. I'm less susceptible to illness if my immunities are strong. I feel this is very similar for plants, which is why I like to provide my soil and plants with all they need.

Healthy plants can fight off pests and disease.

Hopefully they can anyways.

Yes, about once every 2-3 weeks. Its so expensive! I hate when one 1-2 oz item adds $12 to a total. But its supposed to be worth it. Heres hoping!