Fighting Fungus Gnats when Growing Peppers!

During the late winter and early spring is when most gardeners start seedlings indoors. That is, this is when the season actually is starting for a gardener, whether indoors or outdoors, or growing peppers or tomatoes. Well, any vegetable, really! Growing your own kitchen garden plants from seed is super rewarding and can allow you to enjoy unique vegetables. You can’t buy ghost peppers in many super markets, can you?!

Photo by John Tann from Sydney, Australia (Dark-winged Fungus Gnat) CC BY 2.0, via Wikimedia Commons

To bad for me that the fungus gnats alreadey showed up a couple of weeks ago! But this year I’ve set a strategy to fight this buggers off! I know one thing that certainly works, but I have thought of resorting to it as a last resort if my other measures do not work. It ends up with the other words at the bottom of the list, as emergency measure.

So here you can see the plan out for this year:

Gardening sand

A layer with sand on top of the soil in the pot was something I thought would solve all the problems! I was so wrong! The fungus gnats seem to miraculously occur anyway. However, the amount of fungus gnats had probably been higher without the sand so I’ll keep it. It will probably not harm my chili pepper plants!

Fungus Gnats Traps

The traps is made in the form of small containers with a mixture of water, white wine vinegar and a few drops of dishwashing liquid. This is always a good thing. It is actually a lot of gnats who are attracted to the trap, jump down and never comes up again! However, ths will only hold the population at bay not kill them off totally!

Vacuum cleaner

To clear up in the fungus gnats you can pull out the vacuum cleaner and clean all the windows. You can also push the pot with the vacuum cleaner hose so that the flies fly up and then let them be swept away into the hose.

Watering from the bottom up

To water from below, that is to say to let the plant suck up the water from the keg, should be a good trick since fungus gnats likes a moist surfaces. However, it does not sound like a good way before the roots have grown so far down in the pot that they can easily can suck up the water. I will not, in other words start to use this strategy until the plants have grown properly.

Butterfly traps

In addition to the common flytrap, which you hang up I will try butterfly traps also. These traps you stick down in the pot. I have not seen this before, but so far it seems that they can be useful. I don’t know if it is the color of the butterflies (yellow), which makes them attractive, but already after one day have a whole bunch of flies attracted there! Good news!


Nematodes are the only thing that I have tested that really works, so if the strategies above do not make the fungus gnats reduce/disappear I will have to order two bags of the nematodes. Keep in mind, you have to order before it gets too hot outside. A few years ago I made an order and just after that, a heat wave with temperatures over 30 degrees came in, and because my nematodes I got didn’t work, they had likely been destroyed in the heat (they can not withstand such high temperatures).

I know that I am absolutely not alone with that every year fight against the fungus gnats, so I wish you all of the other ”warriors” out there good luck in the war! And if you happen to know a super good strategy, please let me know!

Written on May 13, 2018