Comments on: Fungus Gnats in Worm Compost Bins

By: Night

Night — Mon, 23 Jan 2012 18:56:14 +0000

I just got a plant given to me as a gift because of fungus gnats in the soil, They thrive on moisture, after reading several webpages i still had no answers so i came up with my own after watching how they hatched and headed for wherever the most moister was generally on a wet window surface was generally collecting where the most sunlight was, I soaked a paper towel in vinegar folded it several times as to keep the moister from evaporating too quickly and placed it on the side of the planter where the sun hits, as they hatch they head straight for the paper towel and it kills them almost instantly, However make sure no vinegar gets on the plant as it is also used as a weed killer, In a few days all the new hatch lings are dead before they get old enough to lay new eggs into the soil, Works fast and very effective just add new vinegar as needed,I also found if i put the paper towel down onto the dirt as for a ladder to help them up speeds up the process… I am using apple cider vinegar

By: Richard

Richard — Sun, 20 Nov 2011 04:26:55 +0000

I’ve seen a lot of Venus flytraps appearing on the market in location such as Walmart, Lowes, etc. I’m thinking of combining a little horticulture near my worm farm to fix my gnat/insect problems as they might arise. Has anyone tried or heard news of this being performed yet?

By: mike

mike — Wed, 09 Nov 2011 21:33:01 +0000

Take a clear plastic jar at least 1 quart. Take a peach or grapes and freeze them solid then thaw and crush. Put in the jar and add a handful of fresh grass clippings chopped fine or a handful of alfalfa meal. Add 1/2″ non chlorianated water.

Drill 4 1/8 ” holes at random spots above the line of this mess. Gnats will be attracted in but cannot find their way out. Replace contents every few days as it’s the sweet smell that attracts them. A handful size lump of rotting alfalfa meal will attract 1000′s. Open jar under water un a bucket to kill but outside as many will float up and survive.

By: rap

rap — Sat, 10 Sep 2011 19:14:22 +0000

Hi AM
I really like this web site and all the ideas and feedback that folks offer.

Besides the ideas listed here you may also want to read:
My “Worm Food” post. It might also give you some ideas on how to prevent gnats in the worm bin.

I do think that the moldy moisture of the grinds sitting in the coffee can may have been the problem you were experiencing.
I say this because I have trays of wet coffee grinds drying on racks in my kitchen for both direct feeding in the garden as well as for the worm bins and nothing ever bothers them but these grinds are being air dried and are stirred around not allowing them to get moldy.

By: rap

rap — Sat, 10 Sep 2011 18:53:09 +0000

Hi AM,
Gnats can be so frustrating!

I read that your dad’s coffee grounds are moist. Moist coffee grounds get moldy. Gnats love moisture. I dry my used grounds and then add them.

I lay the dry coffee grounds completely over the surface which I then cover with some dry dead plant material and then I tuck them all in with a newspaper which may be dry or wet depending on the overall dampness in the worm bin.

When I do wet the covering newspaper I then add a dry piece on top.
This does work. The only time I ever have a problem with them is when I don’t do this.

I currently have 2 worm bins side-by-side and one is moister than the other on purpose.
The moister worm bin includes no dry material on top.
It accumulated gnats.
The drier worm bin includes the materials mentioned in the previous paragraph.
It has zero gnats.

I also learned that I have to be careful about how “dry” or “wet” I let the worm bin get.
If it’s too dry the worms don’t do well.
If it’s too wet the worms don’t do well.

I like using the “dry” grounds. There are plenty of them and they are also good for the soil.
I use them directly in my garden beds too. I always use dry so they don’t mold.

My Summary: Dry coffee grounds ARE a deterrent for fungus gnats. Moist and/or moist moldy coffee grounds ARE NOT a deterrent for fungus gnats. Dry coffee grounds together with the correct moisture and toppings work wonders. Read my whole “Gnats In My Worm Bin” article for the whole technique. Notice that there I also specify “Dry” coffee grounds and add “Dry” layers.

Have to find the happy medium.
Sounds like you found yours! Good-luck!

By: AM

AM — Fri, 09 Sep 2011 16:01:10 +0000

The fungus gnats (that is what I am presuming they are) got started in my worm bin. After putting a sheet of newspaper of the top of the bedding material, the problem pretty much stopped. I still see a very few small ones flying around now and then, but I think that problem is basically solved.

My dad keeps used coffee grounds in an old coffee can and throws them out after it fills up. He doesn’t usually close the lid either. It just lays on top of the coffee can. The contents are moist.

The gnats from the worm bin got established in the coffee grounds. I noticed an abundance of gnats around the can and opened it. I saw maybe a hundred and fifty or so pupae and a few larvae. Also a handful of gnats, although I’m sure most of the gnats got out of the container.

Summary: Coffee grounds are NOT a deterrent for fungus gnats (assuming that they were in fact fungus gnats).

By: Grace

Grace — Sat, 06 Aug 2011 15:41:47 +0000

Hi, the first video for Fungus Gnats in Worm Compost Bins, doesn’t work, it is now listed as a “private” youtube video.

Thanks for all the info! Grace

By: rap

rap — Wed, 22 Jun 2011 01:03:03 +0000

Gnats and Worm Bins
The worms and I were doing just well without them. However, one day I screwed up my routine and got them.
Worms love used coffee grounds. Gnats don’t.
I drink way too much coffee and so I make sure to share enough of the used grounds with the worms and I add dry bedding on top of all the damp stuff and then top my bin off with dry newspaper. It’s been keeping the gnats away.
Figuring out just the right wetness/dryness to keep worms healthy and happy and gnats unwelcome and dissatisfied seems to be the key though it can be difficult to monitor in a busy world and so used coffee grinds are a regular additive to my worm bin.
I’ve read that used coffee grounds can make worms hyper but mine have been with me for a year now and they replenish themselves and appear thriving. I’ve even given some away to my relatives to start their own worm compost. Gnats gnats stay away!

By: Gnats In My Worm Bin | Farming

Gnats In My Worm Bin | Farming — Tue, 10 May 2011 16:22:43 +0000

[...] bin experience. What worked for me may not work for you. For more ideas check out this website. Red Worm Composting – Fungus Gnats in Worm Compost Bins It’s full of worm farming ideas, information & problem prevention techniques that may [...]

By: Peter

Peter — Sat, 08 Jan 2011 04:41:23 +0000

For houseplants I’ve found that getting pots that water from the bottom using a wick works (self watering pots). You can then keep the plants watered without having the top wet and feeding the gnats.
Although if you add a lot of water in the bottom, it can go all the way to the top and get the gnats going again. So water as needed, but try and keep the top of the soil dry.

It’s also nice if you have hard water, watering from the bottom stops the calcium crust you can get on the top of the pot.