Battling fungus gnats again, not an extreme infestation, but enough to be annoying. What barrier would you use on the top soil that is not detrimental to my reapers health? Would a heap of perlite be my best bet? I have ordered some mosquito bits and a heap of new yellow traps as well. Would this be enough without having to use a top soil barrier? Thanks 🌱
Best top soil barrier for fungus gnats?
byu/stifisnafu inHotPeppers
by stifisnafu
25 Comments
The only thing that has ever completely stopped fungus gnats for me is a layer of sand on top of the soil. And believe me, I’ve tried everything.
I use HealthStraw garden straw,
Layer of perlite on top will help
This doesn’t answer the actual question but I use 70/30 buffered cocoperlite which does not have gnats like traditional soil. If roots are long enough bottom watering could help as they live in wet soil.
A decent dryback, a top dress of mustard seed meal and adding mosquito dunks , bt, to your water reservoir should clear it up in a week or so.
I had a huge gnat / small fly problem. What worked was SUMMIT CHEMICAL CO 117-6 30OZ Mosquito Bits (Amazon). I poured a couple table spoons in an empty 2-liter bottle and let them soak for 24 hrs (you can soak in a bucket or whatever). I then filtered out the chunks with a screen and watered my plants well with them. Repeat this 2-3 times giving a week or two inbetween. The gnats lay eggs and spend more time in the soil than flying . This is a bacteria that kills the larvae and it’s not harmful to the plants at all. I now have zero gnats. At the same time, those yellow sticky things are great to kill off as many adults as possible. Also, Azamax worked great for my aphids (typical neem oil has never worked for me – Azamax is a strong type of neem). I’m now 100% pest free and my plants are thriving.
I use nothing no cover or mulch on top of mine – just the mosquito bits treatment. I did a treatment in July last year and haven’t had to do anything since. I just had to fully saturate the soil mix when I did a treatment, and repeat again a week or two later. Nice setup, btw!
microbe lift bmc
Mosquito bits is effective,I just used once then after 3days i saw few larvae came out from the soil and watched it died lol. After that i dint see any fungus gnats. I also switch to bottom watering and making sure the top layer of soil is just barely wet,and I bottom water only when top soil just dried out
I would just use Bacillus thuringiensis ssp. Israeliensis AKA Gnatrol
A thin layer of play sand across the top to prevent them laying more eggs. Continue with the yellow traps and treat with your mosquito bits a few times. It’s truly an all out war with the bastards. Make sure you inspect every houseplant you have, as well.
I’ve seen ground cinnamon suggested from a few sources. Not sure if it really works or not
Pepper man
vermiculite if you can get it cheap
Vermiculite on top definitely helps (perlite blows around in my experience), but in the future if you switch to a coco coir based soil then this is MUCH less of a problem. I have been trialing soil mixes with my seed starts this year, comparing coco coir and peat moss – I’m finding significantly less gnats with the coco coir. You’re on the right track with the sticky traps too.
I mulch with cedar shavings. Bugs hate cedar.
Surprised no one has mentioned Diatomaceous Earth (food grade DE).
Autopots have made it a non issue for me since I run salts. I’ll spray the top of the pots with Canncontrol from Mammoth. I have Athena IPM in my res.
A thin layer of milled sphagnum peat moss does it. Sprinkle over at sowing. Prevents damping off and fungus gnats.
Nemasys (beneficial nematodes) and proper watering practices. Dont bother with a top dress. If you have gnats your media is staying too wet. Either because you potted in too large a container or because you are watering too often. Peppers like to dry out!!!
Nemasys is kinda expensive so only really a good option if you are growing at scale but that stuff works extremely well if applied properly.
Washed fine pumice sand. Check often that the fabric pot edges are filled, no gaps.
What’s worked for me is bottom watering with mosquito bits. I’ve still seen a couple fungus gnats, but nowhere as bad as I usually get it.
I grow Aztec Tobacco in my tents. It has an insanely high nicotine content and the leaves literally glisten from all of the trichomes. The gnats land on the leaves and get stuck, as well as being poisoned by the nicotine. Three plants have wiped out the population in my grow spaces.
Once they are aging and near harvest, just brush off the gnats and dispose of their bodies. And the tobacco is good to have around as a natural insecticide. Store the dried leaves and make a tea out of it to dilute as needed and mist directly on the plants. I wouldn’t suggest doing this to food crops that are near harvest unless you want the jitters with your salad but as long as they are rinsed well then it shouldn’t be of any concern. Certainly less dangerous than the chemicals some people use out there.
As for your soil surface, coarse sand (not fine sand as this will aggregate and make a nearly impermeable layer in the topsoil) applied to the exposed growing medium will make laying eggs nearly impossible and the adult population will rapidly die of old age.
I just tolerate the fungus gnats. They used to make their way from the living room to my bedroom, but I put a layer or fone for bark on top, and they are much less in number. Also, I allow spiders in my house, and the fungus gnats will get caught in the web often enough so the numbers are tolerable. I only notice them within maybe a foot of the plants. It’s more biodiversity.
Do a nuke em flush from flying skull and use their Z7 solution in your feed mixture.