i never succeeding in getting rid of them

but i figured out how to avoid them ... check out the link .. sterilize everything .. pots.. tools.. media ... and the watering can ...

you dont say how big your plants are.. but the ONLY sure way .. is to repot them.. and isolate them.. until all the adults are dead ...

i did a bunch of media ... by going to the dollar store.. getting a turkey pan ... putting moist media into it.. and my meat thermometer thru heavy duty alum foil ... and bring it up the the recommended temp ... and it stored for quite a while, as i used it.. and covered as such ... it did not stink up the house ...

i have also done small amounts in a gallon baggie ... until it steams slightly.. since that would be 212 degrees ...

the ONLY time it happened to me.. the plant stand was in the room with the TV.. it was a gnat-tal nightmare..

since my lesson.. i have NEVER presumed that potting media was properly sterilized...

and if you are using garden soil.. well.. that is your base problem ...

good luck

ken

Here is a link that might be useful: link

If you're finding an infestation and haven't prevented one, BTi will take care of them - Bacillus thuringiensis subspecies israelensis - is naturally occurring larvacide (safe indoors) that is often used for biological mosquito control but works great on gnats too. It's not an instant fix, you'll want to use it to water your flats and continue to use it for approx three weeks. Kills the larvae and stops the breeding cycle, the adults don't live that many days and will eventually die with no way to successfully reproduce.

Avail in different products like Gnatrol, Knock Out Gnats (Gardens Alive product) - if you have trouble finding the product you can make your own by floating mosquito dunk in a container of water overnight, then using that to water your seed flats. No measuring with the dunk, it isn't precise, you just want some of the BTi to release into the water so you can introduce it to your flats to kill the larvae.

I keep the granular form of Gnatrol on hand, it has a longer shelf life than some of the liquid products. Not a bit unusual for me to find the gnats in seedling pots outdoors, lots of rain here.

Peaceful, fungus gnats (which is what you have) are not attracted to the vinegar...that's for fruit flies.

Just to add to what Mor suggests about the Bt. Don't do any extra watering with the solution....just use it on your regular watering cycle.

The larvae thrive in extra moist organic-y soils, so you may want to evaluate your watering practices. Peaty potting mixes that are over watered kill more seedlings than fungus gnat larvae.

If what you have is Fungus Gnats the simplest solution to the problem is to watch the moisture levels in the soil. The larva are the problem, although we mostly see only the adults. You can spend money on things such as BTI or allow the soil to dry out more between watering.

Here is a link that might be useful: About Fungus Gnats

Peaceful_Warrior, I take it that you have eliminated 'damping off' disease. Just inquiring.

Ok. Sorry for the delayed answers.

Thanks to everyone for the feedback.

@rhizo_1 - Thanks. I thought I had fruit flies. I used up alot of vinegar & was wondering why they weren't dying. LOL!

@ken_adrian - I think it may be my coconut coir (peat substitute) or it could be something flying in the window screens when we open them. Baking that & the compost may be my last resort.

@ronalawn82 - The damping off stopped after I simply tossed everything & started over. Lol!

Those who suggested BTI, that's not an option for me. I'm trying to go as organic as possible.

So, after some googling here is what I have come up with for those who come after me.

This has not rid me of the problem, but significantly reduced it.

1st - Go buy fly paper. The things you hang up that are sticky. They love this. Place it near the infected soil & the adults will die upon impact. You will notice after a day or 2 how it gets filled up. I left a couple up for about 2 weeks & it had a lot.

Then, as mentioned above, allow the soil to dry. Not too dry, but fairly dry.

While waiting for the soil to dry, apply a layer of sand (course builders - not play box sand) to your soil. This will dramatically stop the adults from egg laying. However, larva are still underneath. Be careful not to add too much sand, otherwise you will suffocate the roots. I noticed that I did this &

Add cinnamon & chamomile tea bags to your watering can. I have a sports water bottle with the squirt top, so this works for me. This will kill the fungus the larvae eat.

Last resort, dilute 4 water to 1 hydrogen peroxide. This supposedly kills the larva on contact.

This is all simply my suggestion from my own experience & I am not an expert. So if someone knows that one of these items doesn't work/is harmful/etc, please feel free to add on.

I am currently doing all including the peroxide & it has significantly reduced my fungus gnat problem.

man thats a lot of work ... when simply bare rooting them and repotting with fresh soil will work for sure ...

just remember for any next time [whatever plants].. think operating room.. and sterilize EVERYTHING.. before you start the operation..

and then you wont have to worry about curing all kinds of problems ...

ken

Bt-I IS an organic solution to the problem and can be used by certified organic growers all over the world. I assume that you don't know what it is.

It's an entirely natural, native bacterium that is reproducible for commercial use; it's been in use for generations. Bacillus thuringiensis strains exist in plentiful amounts in your own back yard. The strain used to control fungus gnats is the same one used for mosquitoes and other insects within the Diptera order....israelensis.

Fungus gnats do NOT eat fungus. They are attracted to the kind of environments that fungi (mushrooms) also thrive in....moist and full of decaying organic matter like leaf mould, peat moss, etc. Typical bagged potting soil is mostly peat moss (fungus gnat food). Think of them as 'bagged potting soil gnats', rather than fungus gnats, lol.

The smartest solutions for controlling these annoying (and damaging) animals is to use a very coarse textured potting mix that has much less peat moss in it. If you visit the Container Forum or the House Plant Forum, you'll get loads of ideas on that. Allow the potting mix to dry out properly between watering, something a bit difficult in peaty stuff.

The use of small circulating fans can also help prevent the humid conditions that these insects thrive in. Sticky traps can certainly be helpful in catching the adults, but Bt-I should be employed if the problem is severe.

@ken_adrian - Yes, it may seem a bit much. However, I have friends who say, "why go through all that effort to grow your own food, when you can just go to the grocery store & get it." Hehe.

Its really not much tho. I'm not so sure its from unsterile soil mix, however, you could be totally correct. I am using the same bags of the same mix that I had used to start some winter sow stuff with no gnat problems. I didn't see a single one. I suspect with the opening of windows (and a couple of screens that need repair) we may have gotten some migrants from a nearby compost heap.

That said, I am dealing with a life cycle that I am trying to stop. Meaning, if I have sterile soil, they will just egg it up & larvae grow, etc.

@rhizo_1 - Thanks for your input on BTi. I'm not going to open the can of worms about what "certified organic" farmers do and how that probably is organic since they do it. Also, its a choice that I make for the food that I grow to feed myself & my family. You or anyone else is welcome to use BTi and I will be fine with it. I've done research on it & it is not for my garden.

But I really appreciate you guys sharing with me these things. It is helping me become a better gardener. Especially you rhizo_1. I'd still be using vinegar if you hadn't pointed out that I had fungus gnats. LOL.