I have been blessed I never had a single gnat the reason for this I believe is the soil I buy is always kept inside at the store if bags are left outside like they do at Walmart it’s almost a sure thing to get them. Even when I buy the bags I keep them in the house a few days before I use it so if there are alive hopefully they die. If you cannot find soil inside and assuming you use soil if there is a way to heat the soil up enough to kill bugs but not hot enough to compromise the soil it’s an idea I just don’t like the idea of chemicals for bugs if possible not to use.
Ok tanks for the reply. Last grows was from clones I got and I was swarmed in gnats from the plants I got. I managed in the end by watering from the bottom and keep the top layer dryer, took me long enough though.
Zero gnats is much better!
Any suggestion to temperature to kill them off in the soil I buy? My grow is seperate from all other plants and stuff and it is winter outside so I should have a fair chance to keep them away if I get clean soil.
You could probably let it go completely dry & that should kill them off. When your growing & get them I know you can water from the bottom with the pot sitting in a saucer & that will get rid of them we’re the top layer goes dry.
Add a 1/4 inch of horticultural sand (do not use play sand) to the top of the soil in your containers, this is unatractive for gnats to lay eggs in and even if they manage to lay eggs its almost impossible for larve to emerge true the sand
When I was growing in soil my thing to have a zero gnat issue was to treat my soil with mosquito bits before my plant went into any container and again after transplant. Final transplant you just shake a little on top of your soil and never saw a gnat again.
Then moving over to the hydro side, you'll never see another bug!