Two things I’m doing that I’ll share that are working for me.
If I already have gnats then I make these traps. People say they don’t want to use fly paper because it is grungy to clean up from but making these was worth it and everything cleans up with a shop hand cleaner like Gojo that contains lanolin and pumice. I make a few more then I need and I lay them out around the stem of the plant. The gnats land on them when flying up or flying down since they are right above the soil. When I had a bad infestation, these became dense with dead gnats and the problem quieted right down.
So, 2 small wooden squares with holes drilled joined by a 5 or 6 inch dowel. Strip of fly paper stapled at both ends.
The second thing I’ve found that works I discovered quite by accident and is much easier and energy saving then baking soil or boiling water. I bought several bags of soil and compost during August to prepare for my indoor winter grow and just left them in the trunk of my car for a few weeks. If its 90 degrees outside it’s probably 150 degrees in the trunk so that will bake it for free and no actual work. My current grow has had no gnats up to week 5 using the “I forgot my dirt in the trunk” method, although that could be because it was properly composted and didn’t have any gnat eggs when I got it.
Talking about Mosquito dunks, I did try them. To make a strong solution I crushed them with a plyers and soaked them in warm water for a few days. It did work but it took a month for that solution to really get a handle on the problem. Later when I got a Ph pen, I tested that solution and I got a reading of 4.0. So, I recommend that you treat Mosquito dunks like any other thing that you add to your soil and test it to make sure it falls into the Ph range that you need.
What is better then misquito dunks is misquitobits. I get it off amazon. I put them in aquarium medium fish net pouches and soak them in warm water for an hour and water with that. It works great!
I put some DE and a layer of these on top of my coco and covered that with a layer of sand. Put some DE on top of that for good measure. No more gnats. I’ve also put Mosquito Bits down every drain in the house to get rid of gnats and drain flies. It’s a little cheaper at Tractor Supply but definitely worth every penny wherever you get it.
I don’t know much but I’ve read that DE works because their crystals have sharp edges that cut into the larva and adult fly which is the MOA. Once the DE is wet then it breaks down and is not any good (I think) when I top dressed w/ DE after a few times the surface became ridged like cement.
I have used the yellow “sticky” paper traps. Have been told the bugs are attracted to yellow color. I fold them over and staple them closed, cut a notch hole at the top and run a wooded post through them and stick that in the pot of soil. I’ve used the bits, kind of a mess, I tried to make a tea w/ them and that was an even bigger mess. I’ve found a liquid solution that I’m going to try. best solution used to date is a KATCHY, uv with sticky trap pad inside below a vacuum.
I too have had that same experience on one of my plants. I am new to using the DE. I let it dry real good and removed as much as I could. If you water from the top (which I occasionally do when I use my organic fertilizers) give it a few hours to let gravity work the water, then top dress with about 1/2" of dry soil. Dust it again with DE and water from the bottom with a little less than you normally do from top watering, the next time or two. Plant seems to get enough water, new top dressing and DE stay dry, until next top watering with fertilizer (which is more of a full watering). Careful not to over-water, and let them dry out a little between waterings, I am finding that judging that is easiest by pot weight. Good and light, with leaves starting to droop, water them. I still get a few gnats, but they die pretty quick, I have to vacuum the tent floor every so often. Hopefully the next crop, with what I have learned, the pesky critters will not be as much of a problem.
That’s great ! one thought is if your catching the adults that are flying then the larvae need to be delt with so they don’t end up growing into flyers, their life cycle is real short, my thinking is to attack them at the earliest before they mature
@Gronasbros, I have never tried that.
As I have stated here, (It least I think it was on this thread). When using a large enough container with soil. The longer dry cycle will kill off the gnats. So I never really need gnat control with soil.
I used to use coco as a mulch for my organic soil grows, easy to scratch dry dry nutrients and castings into it. But I quickly learned that the gnats loved the coco more than soil, and dropped the using the coco for mulch.
I am going to use AutoPots with coco for the first time for both. When at the local grow shop last week, they had an AutoPot on display, and growing plants. So I ask their AutoPot guy, does the top of the coco in the pots stay dry enough to prevent gnats? The answer was no, since the wicking ability of the coco keeps even the surface damp. I said, maybe I will put sand on top of the pots for gnat control. He recommended against that, and said that the weight of the sand would crush, and cause the coco to settle. He pointed out to me that there was rice hulls, (or husk), on top of the pots. He said they are lighter and provide the dry barrier needed to control gnats. I guess I will be giving this a try.
I put a 1.5-2" layer of black sand and mosquito bits on top of my coco early into this grow. I’m at the end and it’s still at the same level in the pots. Hasn’t compacted the coco at all. I have thick wires around the rim inside the pots. The sand and wire are still at the same level. I’m using three gallon pots. Compacting the coco could be an issue in bigger containers, idk.
I am using soil- garden soil with black cow, compost that I have been composting for years (rich in earthworms and casings), peralite, blood meal and bone meal. Being I used garden soil and compost from my back yard I expected gnats. I had them initially and was concerned about other pests. I mixed approx 1 cup 3% hydrogen peroxide and sprayed the soil and leaves of my plants. Within a couple of days all gnats were gone and I have had no other pests. Water is H2O (a two hydrogen atoms with a single oxygen atom)- hydrogen peroxide is H2O2- essentially water with an extra atom. The pests appear to hate it and my plants had no ill effects. Happy Growing
This is one of the reasons I go hydro and why I’m using rocks. I have had gnats with every damn thing I’ve ever grown in soil indoors and they drive me crazy. I never had gnats in the old days and I don’t have any now even though I think there’s some in the house from my house plants. Don’t know what would happen if they try to lay eggs but I haven’t seen any yet or any in my sticky trap. Supposedly they don’t bother the buds but I had them with the plant I grew in soil just before I went with this hydro set up and found a couple gnats stuck to a couple of buds which grossed me out. I even microwaved all the soil I used in the last few indoor plants and I still got gnats. I have sprayed the crap out of my plant soils with the neem oil mix and it hasn’t hurt any of them but I wouldn’t put it on a budding plant. I’ve tried everything and I can’t get rid of them I just hope they don’t like hydro rocks.
