Fungus gnats are a continuing problem. If they are in the environment outside your grow, they will find their way inside. For me that starts in spring and runs until first frost. People seem to love blaming soil brands for bringing FG into their grow room. Crazy. Fungus gnats are everywhere. Probably more likely to come into your grow room in your hair than in your soil.
Fungus gnats used to be considered a minor irritant - mostly to the grower. A healthy adult plant will probably survive an infestation. Starting plants will have problems. Fungus gnat larvae eat root hairs. This will slow mature plants. It will stop cuttings or seedlings from rooting.
Good news is that they are easy to kill. Lots of stuff will do it. Better news is that Gnatrol will kill them 100% of the time and it isn't toxic. 3 weekly treatments with a teaspoon of Gnatrol per gallon of water and it's done. You won't see any evidence of the gnats 24 hours after the first treatment. Keep it up though. The bacteria only last for a day and you need to get all of the larvae as they hatch. No harm, no foul.
Sort of. Gnatrol is expensive and it literally smells like shit. It gums things up. You don't want to ingest the spores, blah, blah, blah. For these reasons, I want to minimize my use of Gnatrol. I keep it on the shelf at all times.
Yellow sticky traps will kill some adults but it's better to think of them as indicator instead of treatment. Do use them. You will see the little bastards crucified on a sticky trap before you ever see one in flight.
I grow in soil - 2 parts Happy Frog, 1 part Perlite, right now. I start seeds and cuttings in beer cups, move them to 1 gallon #1 pots and finally to 5 gallon pots for flowering. I can effectively prevent fungus gnats in every container but the beer cups.
Fungus gnats need to be able to move between the soil and the air above it a few times during their life cycle. Creating a boundary through which they can't pass at the soil air boundaries stops them from developing and reproducing. The areas of concern are the top of the pot and the drain holes in the bottom. I make sure I use posts with 4 drains.
I build my barrier using fiberglass screen mesh and pea gravel. This is really a variation on the sand on top of the soil technique. I tried that and it worked but watering was more difficult than before. Sand washes out even more easily than soil.
I cut fiberglass mesh squares for the bottoms of the pots. The length and width of the square should be equal to the diameter of bottom of the pot.
I cut a fiberglass mesh circle for the top of the soil. Diameter equal to the diameter of the top of the pot. Circle is split from outer edge to center for stem.
Fungus gnats used to be considered a minor irritant - mostly to the grower. A healthy adult plant will probably survive an infestation. Starting plants will have problems. Fungus gnat larvae eat root hairs. This will slow mature plants. It will stop cuttings or seedlings from rooting.
Good news is that they are easy to kill. Lots of stuff will do it. Better news is that Gnatrol will kill them 100% of the time and it isn't toxic. 3 weekly treatments with a teaspoon of Gnatrol per gallon of water and it's done. You won't see any evidence of the gnats 24 hours after the first treatment. Keep it up though. The bacteria only last for a day and you need to get all of the larvae as they hatch. No harm, no foul.
Sort of. Gnatrol is expensive and it literally smells like shit. It gums things up. You don't want to ingest the spores, blah, blah, blah. For these reasons, I want to minimize my use of Gnatrol. I keep it on the shelf at all times.
Yellow sticky traps will kill some adults but it's better to think of them as indicator instead of treatment. Do use them. You will see the little bastards crucified on a sticky trap before you ever see one in flight.
I grow in soil - 2 parts Happy Frog, 1 part Perlite, right now. I start seeds and cuttings in beer cups, move them to 1 gallon #1 pots and finally to 5 gallon pots for flowering. I can effectively prevent fungus gnats in every container but the beer cups.
Fungus gnats need to be able to move between the soil and the air above it a few times during their life cycle. Creating a boundary through which they can't pass at the soil air boundaries stops them from developing and reproducing. The areas of concern are the top of the pot and the drain holes in the bottom. I make sure I use posts with 4 drains.
I build my barrier using fiberglass screen mesh and pea gravel. This is really a variation on the sand on top of the soil technique. I tried that and it worked but watering was more difficult than before. Sand washes out even more easily than soil.
I cut fiberglass mesh squares for the bottoms of the pots. The length and width of the square should be equal to the diameter of bottom of the pot.
I cut a fiberglass mesh circle for the top of the soil. Diameter equal to the diameter of the top of the pot. Circle is split from outer edge to center for stem.
