Transplanting with Fungus Gnats?

New forum member so apologies if this isn’t posted correctly.

This is SWIM’s first attempt (indoor) and he noticed a fungus gnat in the soil of his Gorilla Glue (ILGM) a few days ago. Yellow sticky tape was put out the day after the first gnat appeared and a dusting of DE was just applied today as soon as the package arrived. So far the tally is at 5 gnats caught by the tape within 3 days. The problem came due to poor drainage in crappy soil that was already on hand because SWIM had no access to quality soil until it was restocked online (health condition so shopping in-store is not a great option during this whole… situation). SWIM would’ve waited for quality soil but the GG is for medicinal purposes and time is of the essence due to a newfound lack of medication, so the grow began anyway.

The plant is doing well enough with EXTREME TLC to compensate for the soil issue until a few days ago when the gnats were spotted. Temp and humidity were consistently in the recommended range the entire time. So far there are no visible signs of distress from the plant besides a slowing of growth. Obviously watering habits are an issue because of inexperience but it’s overwhelmingly due to the poor drainage and the fact that the average outdoor humidity sits between 77-89% every day. New soil of good quality came in the mail 2 days ago but SWIM has been waiting to gauge the gnat situation before transplanting to the 3rd and final container. There are spacial limitations so it’s getting close to forced flowering time.

The problem is that the fungus gnats will be very difficult to fully eradicate in this absolutely garbage soil that refuses to dry out completely, yet there would be a great risk of contaminating the new soil with a transplant. It’s practically a catch-22 situation.

What should SWIM do? Given the life cycle of fungus gnats it would seem like waiting 3-7 days for the DE treatment and sticky tape to take effect would be the best course of action, however with the spacial limitations there is a fear the plant will become too large by that time. With the gardening inexperience and the already-present stress on the plant, training sounds like a bad idea.

Yes, next time high quality soil will be used right off the bat so there’s no need for a lecture on that front. This was a moment of dire circumstance in the pursuit of symptom relief and peaceful sleep. Any and all expert advice is greatly appreciated.

Thanks and stay safe out there.

You don’t really have a big fungus gnat problem. If you’re only getting a few on the sticky pads you should be ready to move forward.

A fungus gnat problem is when you open the tent and they are flying everywhere. I ran into that problem over the winter. A bad fungus gnat problem will take a toll on the plants. I let the pots dry out really well and started the move my fingers through the top inch or two of soil. That seemed to keep them in check. I refuse to use any kind of pesticides to treat a bug problem.

I still have a few fungus gnats flying around. I think it’s acceptable if there is only a few. The fan does a good job of taking them out.

They don’t seem to bother my plant.

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The problem with fungus gnats is not the ones you see flying and walking around, it’s their larvae in the soil feeding off your root fungus that’s the real problem. When I get fungus gnats (just had some recently), I use Mosquito Bits to kill the larvae in the soil and dust the top of the soil with DE as well as the yellow sticky traps.

If your plants are in need of a transplant, go ahead and do so and then use the Mosquito Bits and DE.


I can tell you what not to use! I just tried GoGnats after the hydro shop recommended it. Here is what happened when I poured it into my reservoir. It created fatty deposits that caused me to drain my system and start over, because I didn’t feel good about allowing it to be pushed through my system. I wish I would have taken a pic of my reservoir.
I did however mix a spray bottle of it and it was just fine.

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BTi will work wonders. If it gets really bad nematodes are a Great solution but you’re not there yet. A few is natural - their going to be there if you grow outdoors you just don’t want an infestation - higher population that what you would see when you go outside

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That does look like a happy plant.

Thanks!! The transplant went smoothly and so far the gnats are at bay.


Good to know lol.