So I grow organically and am kind of doing no till but in medium size containers(15 gallon).
Ive had some insane problems with fungus gnats and I can’t seem to get rid of them. I’ve used neem/karanja, essential oil IPM, nematodes, ladybugs, and eventually mosquito bits. The mosquito bits worked great but still have gnats.
Im thinking about trying gnat nix. I take all my leaves I trim and use them as green mulch, could I just move the nix aside and put the leaves under and then cover up again? Also with top dressing with dry nutrients, EWC, etc am I going to run into any problems?
Pick your control methods. Predators and pesticides don’t mix.
I would repot. Remove as much soil as possible. Rinse with mild stream of water than dip and repot. Use control methods as described below. Until issues are resolved. Don’t buy the hype some fungus gnats are not that bad and are unavoidable. BS, you will not work for me.
Microbe-lift BMC – 1-3 drops per gallon.
Pyrethrin – dip roots and or spray soil.
Dry top soil – stop over watering
Stop mulching
Monitor with yellow stickies
Air movement
In hydro – tips
filter solution through 45 micron silk screen. Rinse screen daily may dip in oxidizer.
Drain reservoir leaving a few inches. Gnats stay on top discard top or pass electric current through to kill. Consult a certified professional electrician or don’t do this.
Determine where the gnats came from in the first place and remedy. Environmental controls to avoid issues in the first place. I find most come from:
Cloning areas and root cubes
Infected soil.
Standing water
Remedies
Pressure cook (autoclave), boil cubes
Autoclave or bake soil
No standing water anywhere
Gnats are hard to get and even harder to get rid of.
Good luck
When you first fill your pots, put some landscaping fabric on the bottom so that it covers all the holes (that way the little buggers can’t get in or out that way), fill with your regular medium but leave an extra inch on the tops. Fill around a 1/2 inch to an inch of sand on the top of your medium, this acts almost like glass shards to them and will cut them up if they are coming from your soil and it will keep your tops dry. When you want to add leaf mulch just scrap away some of the sand to add your mulch and then bring the sand back over the top.
If you are opposed to using the sand, you can use landscaping cloth cut to size on top, but it might be hard to make sure there are no little folds or spots of the soil that aren’t covered.
Either way, it is a low cost, non-toxic way to help control fungus gnats.
Repotting isn’t going to work as I’ve got less than two weeks until harvest, I’m trying to plan for next grow.
I’ve got some organx pyrethrum spray though I haven’t wanted to use it indoors, I’ve got pets and I’ve read not to use it in homes basically.
Looks like Microbe life BMC is similar to mosquito dunks/bits which I’m using but I’ll buy some of that stuff since I’ve run out of dunks.
I use yellow sticky traps
I’m in living soil so I’ve got to mulch and the soil is always damp, really no way around that.
I don’t clone or get plants from anyone else so it’s coming from my soil mix for sure.
And I don’t want to autoclave or bake soil(nor do I know how) since I don’t want my soil to be sterile but full of life. Obviously this brings pests but I’ve had a hell of a time getting rid of them.
Thanks Sticky!
Spartan grown
I use fabric pots so no holes in the bottom!
I’ve got about 4” on the top of my pots right now so I can easily try the sand next grow, thanks!
When I had gnat problems, I had to change my gardening habits. I needed to make sure that the top layer of soil was not an ideal environment for the gnats. I was watering a little too often (in hopes of not letting my microbial populations die off) and keeping my very top layer too moist. My plants were happier than Dude at a t-top Camaro convention, but the gnats were pretty stoked too. The two methods I went with were planting a cover crop or mulching with my bokashi rice hulls (bokashi bran but I use hulls for the silica benefits). Once I stopped having an unprotected moist soil layer on top of my pots, my gnat numbers went way down. In the SIPs I use in the flower tent, I never have problems, so my problem was mostly a watering error on my part. HTH
And I am not hating on Dude. I would also be at said t-top Camaro convention jealously looking from a Fiero or an old Pacer.
Gnats are a pain. Last resort – serious now. Hydrogen peroxide. 32 oz mixed into 96 oz of RO or filtered water & dump it all into your soil. You plant roots will love the extra oxy. BUT BUT BUT… This basically will kill off most of the good mojo in your rhizosphere so you’ll need to follow that application, once it dries out with a heavy dose of Recharge or compost tea OR BOTH.
I’m a bit surprised the nematodes didn’t get it done. Did you give them enough time? Did you use SF nematodes? Nematodes need a good bit of time to work. I would suggest, if you go this route, blast the H2O2 into your soil & when you rebuild your soil biology you add the nematodes back in also.
In my experience, gnat nix didn’t do a damn thing. The gnats crawled through a 2 inch layer of it like it wasnt even there. It did scrape up my arms and irritate my skin though. (I completely hated gnat nix. I don’t recommend it.)
To 100% eliminate gnats, the key is PERSISTENCE and PATIENCE!
You have to break the life cycle and stop them from reproducing, and this can take a few weeks of constant treatment.
How to break the cycle:
1) Deploy sticky traps to catch as many fliers as you can (helps prevent future eggs being laid)
2) Use a BT product to drench the soil. Use it every watering for a few weeks. Microbe lift BMC is the best I’ve found. (This kills larvae in the soil)
3) Deploy Predators- Nematodes are good but it usually takes more than one application. add some Predator mites and rove beetles to murder any survivors and to help with long term prevention. (This kills any survivors and introduces a predator to keep the gnat population down for good.
4) Make sure you treat ALL SOIL OR MEDIA around your grow! Bags of unused soil or soil in storage can harbor a gnat infestation, even if you don’t see gnats. You have to treat ALL media not just the plants you know are infected.
(One time I had gnats in my grow and I couldnt seem to get rid of them. I was treating all my plants and they would go away for a while but they kept coming back. Turned out the gnats had infected my worm farm, and then the gnats from there were reinfecting the rest of the grow. Once I started treating the worm farm and the soil I had in storage the problem went away and I was gnat free.)
Teeth,
Great, at least make the switch to Microbe Lift BMC. You will not be sorry. The bites and dunks are mainly endotoxins of the bti, which work great for 1-3 days, not the 30 they say. The spores don’t inoculate and live bacteria is already dead. Not only that they are most likely harvested well past death phase (log phase will give you live inoculate) and mixed with a starch base witch than feed the gnats. It’s a win loose situation. Kill them feed the ones that survive.
PS Throw out the unused Microbe Lift after 12 months.
Soup likes it and so do I
I brought home some and have been dealing with these mutants which do not die using BTi, neam, azamat, etc. or didnt for a while until I got their shit dialed in. First, screw fliers that’s a waste of time. Seriously don’t screw with them well deal with them shortly. First get fly tape in rolls, the yellow. Cut out enough and put it on your soil covering it all. Next, to deal with them takes 3 days of treatment. Mix 2 tsp JMS Stylet Oil + 3 tsp Takedown or whatever pyrethrin you pick and that’s into a 1.5 liter spray bottle. Spray your soil in the morning completely and reapply sticky tape. Repeat for 3 days, 4 to be certain but I eradicated them from my plants in 3. If you spray the leaves too, do it prior to lights on and use a little dish soap to emulsify. I sprayed the leaves too and pests (whiteflies, fungus gnats, etc.) outdoors disregard the plants completely, like they actively avoid but that doesnt work in flower.
There is a lot of great advice here already.
I couldnt beat the gnats. They repopulated insanely fast. Sticky traps would be full within 2 days.
I finally beat them now. I used neem powder. Mixed it through my soil and putting a layer of sand on top of my soil. Within a few days problem solved.
I really appreciate all the input crew. Sounds like I need to get some Microbe Lift, more predators, neem meal, and some sand. These bastards are crazy!
if u want to control them out use peroxide you can spray undiluted. i have sprayed a whole small bottle on the soil surface of a 10 gal pot then sprinkled cinnamon generously over soil trying to miss the plants and let it dry out b4 next watering. after u will need to reinoculate with recharge and any other microbes u may have, i make my own LAB and FPJ which helped get rid of little bastards. remember just because your in notill does not mean you have to keep it moist on top layer of soil. i use a popsicle stick and push it into the soil to feel how far down its dry once top 2 1/2 – 3 inches is dry its time to water and also try to use something that will help the soil stay evenly moist and prevent it from becoming hydrophobic yucca or aloe filet blended into your water is great for doing just that but dont hold back, some dr bronners may help too but i have not tried that yet because since the peroxide/cinnamon treatment i haven’t seen but one gnat best of luck and growers love!
I use a product called t drops. I havent seen one gnat this grow