Gnats, Gnats, Gnats, how do I get rid of them?

[BlueCrabGuy]

Hi Growers,

I'm seeking advice on effectively eliminating or managing gnats in my gardening setup. I employ an Earth Box filled with Build A Soil, incorporating soil and amendments. To address the gnat issue, I apply Gold Mustard Seed Meal on the soil surface and maintain a plastic cover over it. Additionally, I utilize yellow sticky traps. While the Earth Box supplies water from the bottom, I occasionally water from the top when adding amendments. I anticipate harvesting the plants in the first week of April. Any suggestions would be greatly appreciated.

Do gnats cause any problems or are they just a pain?

Thanks,
BC

 

[DeadheadJim]

I bought a bag of live ladybugs a few weeks ago. No more gnat problem. I put a few of those yellow sticky pads in there before I got the lady bugs.

 

[BlueCrabGuy]

I bought a bag of live ladybugs a few weeks ago. No more gnat problem. I put a few of those yellow sticky pads in there before I got the lady bugs.
View attachment 2123734

Thanks! Do the Lady Bugs die off after you harvest? Visions of Lady Bugs throughout the house. :)

 

[DeadheadJim]

Ladybugs are good luck. I got a bag of 1500. With shipping it was $30. I did not release them all. They will keep in the fridge for about 4 weeks. I vacuumed the tent yesterday. Yes there was some dead ones. They seemed to have stayed in my daughter's bedroom where the tent is. I'd rather see ladybugs then stink bugs.

 

[LoveGrowingIt]

Baking soda kills them. Sprinkle it lightly on the soil and then spray it with water so it soaks into the top of the soil. The gnat larvae eat it and die. They have a 17-day life cycle, so repeat 2 or 3 times, or until no more gnats appear. I used this method for my current grow that I also expect to harvest in April. It worked perfectly. The best thing is it is quite inexpensive and baking soda can be found in most kitchens.

 

[Natep]

Natures good guys has a control by pest section. Good info on what nematodes eat the larva.

 

[Purfict]

I was battling fungal gnats for a few weeks, did Dr Zymes soil wash, fly traps from the top of the tent, neem oil, and baking soda. I would say the dr zymes worked ok, didn’t see any for a few days. Baking soda worked for a day or two, but what solved the problem for good (hopefully, it’s been a few weeks of not seeing any) was nematodes. I only got 5 million, split it in half and did waterings about 2 weeks apart.

 

[Derbudd420]

Gnatrol does the best imo

 

[PahPahCee]

Mosquito bits. Add a few granular bits to your water every other week and you won’t see anything.

I even throw a few granules on top of my capillary mat (gnat breeding ground) and I have no issues.


Cheap, safe, and effective.

 

[Purfict]

Mosquito bits. Add a few granular bits to your water every other week and you won’t see anything.

I even throw a few granules on top of my capillary mat (gnat breeding ground) and I have no issues.


Cheap, safe, and effective.

I would recommend letting them sit in the water you plan to feed with and sift them out before just so they don’t go mushy sitting in your medium.

 

[LoveGrowingIt]

Baking soda worked for a day or two,

It must be repeated. That's because it doesn't kill the eggs. It only kills the larvae. The gnats have a 17-day life cycle. I used it once a week. The last time was on the 17th day when I saw one gnat flying. Since then, I haven't seen any.

I think the best way to use it might be to apply it when you see gnats flying, because when they're flying, they're making more gnats. I've managed to kill the flying and crawling gnats by spraying H2O2, but that doesn't kill the eggs and larvae in the soil, so they come back. Killing them while they're in the soil is the key, I believe.

 

[PahPahCee]

I would recommend letting them sit in the water you plan to feed with and sift them out before just so they don’t go mushy sitting in your medium.

I throw them in a rosin mesh bag and throw that in my reservoir. Paint strainer works just as well.

If I’m lazy I’ll just throw some on top of my medium. I’m in soil so it doesn’t cause any issue for me.

Less is more. You don’t need much.

 

[Purfict]

I use fox farm OF and HF and they’re both attractive homes for gnats. I plan on using them for at the very least my next grow or two, so my plan is to use yellow traps and mosquito bits from the very beginning to try and prevent the issue.

 

[dreamnfox]

Amazon.com

this stuff, it is amazing. I few drops, i do six in a gallon, will kill the larvae in the soil. I use Blumats, so the soil stays moist, i little of this in my rez and in 2 weeks, no more gnats, get a few of the yellow sticky traps to catch the fliers.

 

[stanknkatz]

Diatomaceous earth liberally top dressed on your soil. Gnats climb up out of the soil through it and it cuts up their exoskeleton and they die. Repeat in a week to 10 days or so to catch any subsequent hatches. Loses its effectiveness when wet.

 

[dreamnfox]

Diatomaceous earth liberally top dressed on your soil. Gnats climb up out of the soil through it and it cuts up their exoskeleton and they die. Repeat in a week to 10 days or so to catch any subsequent hatches. Loses its effectiveness when wet.

I have tried that trick quite a bit but it doesn't really seem to work well, plus of you need to water frequently the stuff barely drys out

 

[Putthataway]

I have tried that trick quite a bit but it doesn't really seem to work well, plus of you need to water frequently the stuff barely drys out

I was amazed at how fast it was effective. I didn’t get the burns from neem oil and was a lot quicker results.

 

[BearWater]

Diatomaceous earth liberally top dressed on your soil.

Would there be any benefit to adding it to your soil when mixing before a transplant? Or would it negatively affect the soil/roots uptake ability, or maybe just not even work?

 

[Jumpingspider]

Microbe lift bmc kills the babies sticky traps for the adults

 

[Putthataway]

Would there be any benefit to adding it to your soil when mixing before a transplant? Or would it negatively affect the soil/roots uptake ability, or maybe just not even work?

It adds silica and has calcium. I have heard it can mess with ph. I am growing in organic soil which has buffers for the ph. I was really skeptical about it. I will probably be tossing it outside in the summer when the ants arrive.