Cause of fungus gnats – where do they come from?
Fungus gnats: tiny, black flies that seem to appear out of nowhere and bother you and your plants. They often are delivered either in the plant itself or in the soil you might have bought. Once they invaded your space – they are here to stay and are etremely hard to get rid of. One grown fungus gnat can lay up to 100 eggs. They favor wet soil because their eggs can develope better in it and their lava can develope better. They are not only annoying as adult flies but their lava eats from your plants – more percise from their roots. That means they harm your plant and annoy you a lot while doing it.
How can you get rid of fungus gnats?
There are multiple things you can do to reduce the fungus gnat population and hopefully eliminate them in total.
1.Matches: Place one or two matches (depending on the size of the pot) head first into the plant pot. The sulfur in the match will help to get rid of the larve in the soil. It’s important to treat all plantpots at the same time tho because the grown fungus gnats will otherwise just switch to the next plant.
2. cornivorus plants: I think that one is rather self explanatory. Given that one fungus gnat can lay 100 eggs you have to get rid of all the grown ups and cornivorus plants can help with that. I can recommend either common butterwort or sundew -simply because those two can eat a lot and are easy to keep happy.
3. Sticky card – traps: Sticky card trapps are basically yellow cards which are sticky and they attract the flies. Once they land on the paper they cannot get away anymore. You can either buy them on amazon or in a local store or you can make a DIY version by putting a small amount of honey onto a stick it. It isnt as efficient as the Sticky card but it will still get some adult flies.
4. The chmical bomb: There are some liquids you can buy online that will kill off the larva of the fungus gnats. I have used them and I am a fan of Neudorff Spruzit Trauermückenfrei but I would not use that if you have animals or want to consume whatever you plant produces. Officially you can and it’s supposed to be okay but I really dont trust that. Anyway, it kills of the gnats larva and is easy to use. You simply add it to the water and us it every few weeks for at least two times. In beetween the usage you are not allowed to water normally. I would recommend using it in fall or winter only. In summer its hard on the plants depending on the temperature.
5. Coffee ground or Quarz sand: A way of preventing the grown fungud gnats to have offspring is to make sure they can’t ley eggs into your plants soil. This can be done by adding any “top” to the substrate. Coffe grounds are in my opinion perfect for that, because they fertilize the plants in addition to preventing the fungus gnats from laying eggs. If you have other plans for your already used coffee grounds you can just add quarz sand or any other sand that is very fine and heavy so that the flies cannot lay eggs into them.
6. Carnivorous plants: I loooooove this option. Just get some sun dew or venus fly trap and enjoy seeing your carnivorous plants flourish while fungus gnats slowly disappear from your house. It really is a win-win situation for all your plants and the meat eating plants will also take care of any other flies like mosquito and such. Only downside – not everyone is “good” with those type of plants. They need more sun and different water and are not necessarily the easiest for everyone. I think sun dew is simple enough to try even for a beginner tho.
7. Bottom watering: Fngus gnats love it moist. The adult gnats don’t really dig deep while laying their eggs so the larva is in the first 2 cm of the soil. Bottom watering means you only put water into the pot not the substrate so the plant can take whatever amount of water they need through the drainage holes on the bottom. That helps to prevent the infastation by drying out the first few layers of substrate. Similar to the Coffegrounds-method the adult fungus gnats can’t dig into the ground anymore and the larva can’t move around in the ground as well as before.
Given that they can multiply quickly and one adult can have up to 100 kids you have to get adults and larva alike If you want to get rid of them. It’s best to combine at least two of the methodes to 1. stopp the reprodution of the gnats and 2. kill the larva. I mostly use my carnivorous plants to get rid of the adults and then only bottom water to prevent a new infestation and stop larva from hatching. I also do the coffegrounds every now and again but that is more for a natural fertilization and double usage to stop waste. You should also make sure to not overwater your plants and if you do – get rid of the excesswater from the pot. Not only do fungud gnats love that – your plant could actually rot from the bottom up. Good luck and if you now any other method please let me know so I can add it to the list. Let’s get rid of those litte bitches!