Gnats Appear When Soil Dries Out

[Minitiger]

Have you guys ever seen this? It's always been my understanding that gnats typically start to show up when the medium one is growing in is too wet. I water every other day, but I do sometimes get lazy and skip a watering. Lately, every time I've done that, the next time I water (the third day, as opposed to the second), I've noticed little gnats flying up out of the dirt. Once I get back to my "every other day" watering schedule, they disappear, usually after the second time I get back to the every-other-day thing.

My plants look great, so I don't think they're affecting them at all. And it's not like I'm being overrun with them, there's just a few here and there. But I do think it's weird how they show up when my soil dries out a little, as opposed to when I keep it moist (moist..... gross.... I hate that word haha). Anybody have any idea what this is about?

 

[Minitiger]

Sorry, I should have added that I'm growing in organic soil (Equal parts peat/compost ((this batch is a 50/50 mix of EWC and Bu's Blend)) and pumice, with the usual added amendments), with barley mulch on top of that. I do also just throw the leaves that naturally fall off on top of my mulch layer, but I always do that and never seen gnats before. The only thing I can think of is maybe it has something to do with the Bu's Blend? First time I've used that in a soil mix and my plants are loving it. Like I said, the gnats don't seem to be affecting my plants, but they still bug me (no pun intended)(seriously, no pun intended haha).

 

[DrMcSkunkins]

Pull the plant gently out of the pot and scope the roots with a handheld microscope, sounds like it could be root aphids.

 

[Major CBD]

I'm driving right now so I'm using voice to text. When you water you're not seeing them because you're getting the bugs what. If you are doing in soil like I am using organic amendments then you are going to see biology even if you don't want to. My suggestion is to get the paper sticky traps and put them on top of your soil after you water. When the larvae mature they will hop on top of the soil until their wings are strong enough to fly around your room. I'm headed to my garden now. I'll take a picture for you

 

[Major CBD]

I may see one or two fly around in my room when I open up my tent. That's because only one or two out of a couple hundreds make it to be that strong.

 

[Major CBD]

Sorry, I should have added that I'm growing in organic soil (Equal parts peat/compost ((this batch is a 50/50 mix of EWC and Bu's Blend)) and pumice, with the usual added amendments), with barley mulch on top of that. I do also just throw the leaves that naturally fall off on top of my mulch layer, but I always do that and never seen gnats before. The only thing I can think of is maybe it has something to do with the Bu's Blend? First time I've used that in a soil mix and my plants are loving it. Like I said, the gnats don't seem to be affecting my plants, but they still bug me (no pun intended)(seriously, no pun intended haha).

The one thing I would like to add about the gnats. It's the larvae you need to be concerned about. The munch on roots that limit the plant's abilities to perform. You won't see the signs in the leaves like you would with leaf miners of thrips. I also avoid peat. when you start recycling your soil or perform no-till practices you might have some problems.

 

[Freshone]

Bacillus thurengensis/BT is your friend,it can be had in liquid or in mosquito dunk form.

 

[DrMcSkunkins]

I use bti neem and spinosad and it seems to have no effect, they just get worse and worse until I break down and get nematodes.

 

[EventHorizan]

One things for sure,, before you can call yourself a accomplished grower, you have had to have had the fight of your life against one or more of these critters,,,,( as granny would say....)

 

[Major CBD]

When you are growing using organic methods be very cautious about what you add to your environment. Advice about sprays and adding stuff to your soil can be very dangerous to your microbiology.

 

[Major CBD]

The big pad on the left was in there for four weeks. The one small one has been in there for 2. Put those pads to work. I only had 1 flying around when I opened up the tent today.

 

[justiceman]

When going organic it's pretty common to get fungus gnats with a soil or compost so it's likely they could have come with the bu's blend. It helps to lay the mix out in a kiddie pool before using or something of the sort and let it kind of dry out(not completely of course) so the adults fly away and hopefully all the larvae dry out and die.

Best you can do right now without adding anything to your feed water is yellow sticky traps for the adults, and potato slices on top of the soil. The larvae will be attracted to them. Once you see some on the slices you can toss em.

 

[DrMcSkunkins]

You could hit the fliers with the hair dryer on the high heat setting, thx to @One drop

 

[Minitiger]

Pull the plant gently out of the pot and scope the roots with a handheld microscope, sounds like it could be root aphids.

The plants are pretty big; I have them in seven gallon pots. Plus, they're really close to being finished, maybe one week away. Honestly, I'm not too too concerned about it, like I said, everything's looking good. But thanks for that. Now I know if this happens again.

 

[BionicKroniK]

When you are growing using organic methods be very cautious about what you add to your environment. Advice about sprays and adding stuff to your soil can be very dangerous to your microbiology.

Hhmm...You just gave me an idea...DUCT TAPE!

 

[MagicSeth]

Go to the local pet supply store and get some Fish Tank sand and a layer to the top of your pot and water. IF ONLY YOU COULD HEAR THEM SCREAM...Try it . It might work. You have nothing to loose.

 

[ShaunDogg83]

I’m a big advocate of diatomaceous earth. It gets rid of insects, is natural and non toxic, can be used to condition soil and helps plants absorb nutrients. I’ve been mixing it in with topsoil/perlite/vermiculite and my plants are loving it!

 

[Jonjr]

I’m a big advocate of diatomaceous earth. It gets rid of insects, is natural and non toxic, can be used to condition soil and helps plants absorb nutrients. I’ve been mixing it in with topsoil/perlite/vermiculite and my plants are loving it!

Does it work with coco coir too? I’m using mint but doesn’t seem to work.

 

[RJenZen]

I’m a big advocate of diatomaceous earth. It gets rid of insects, is natural and non toxic, can be used to condition soil and helps plants absorb nutrients. I’ve been mixing it in with topsoil/perlite/vermiculite and my plants are loving it!

I was just going to suggest DE also. Not only will it clog and suffocate the insects breathing holes, it's also a good source of silica I believe. I'm on my first grow after 30+ years smoking. Growing in hydro but seeing 1 gnat got me nuts (killed it with my bare hands ☠, former Marine ) . I treated my hydroton with neem oil and DE. Put out the yellow sticky. It caught 1 gnat on the sticky and I haven't seen any since. I'm indoors in a tent. Any infestations would have wifey go full on OCD. She wouldnt let up till it was all gone. When we discovered the gnat source to be a bad onion in the kitchen, she kinda STFU real quick.

 

[Edinburgh]

Go to hardware store! Buy bag of food grade de earth $6 bucks, let your topsoil dry completely this stuff is powder and must remain dry to work properly, once your soil is dry sprinkle the powder around plant, you can wad up some tp and dust the fans, do Not dust flower! Leave for 72 hours, give a light flush check ph and you should be straight, i never use neem de is cheap organic and will kill any pest with an exoskeleton pronto, will even give your plant a bit of cal/mag i use it exclusively if the pest has an exoskeleton it's toast.