I have a lot of plants in my collection, this summer one of them got infested with fungus gnats and now all of my plants have them flying all over, I’ve never dealt with it so I’m not sure what products would work. I water them on a normal schedule None are waterlogged and get enough sunlight so I’m not sure why it’s spreading but advice would be appreciated
by sheabae200216
10 Comments
there is a specific type of worm that will eat the larvae of the gnats you should look into it
The portulacaria in the photo will rot if you keep the soil wet enough to breed fungus gnats. Let the soil dry out and stay dry a couple of weeks between waterings. Wait longer in the winter. Then the plant won’t die and as a bonus you won’t get fungus gnats
The soil should dry in about a week, repot in grittier soil if it takes longer
I bought my daughter a zevo light. She has the yellow sticky things too and they just weren’t enough. Daughter didn’t think the light would work but after a week we could see the bugs stuck to the sticky insert. We also use a [peroxide solution](https://plantcaretoday.com/fungus-gnats-hydrogen-peroxide.html) in the watering process to get the gnat eggs.
Now we are 3 weeks in and use all three forms of treatment and are not seeing the gnats very often and expect they will be completely gone within the next two weeks.
Watering on a schedule isn’t necessarily recommended as each plant has different needs. The plant could appear dry but still be waterlogged down an inch or two.
Sticky pads are good for adults. Depending on where you live you could purchase Mosquito Bits/Dunks(crush them up),diatomaceous earth (soil needs to be dry for it to be effective), nematodes.
Killing the larvae isn’t instantaneous so it’ll take a few cycles to get them all. As annoying as they are, it’s not the most devastating pest to have. More of a nuisance. I honestly always have at least one or two gnats floating around but I try to water with bits once a month or so.
You could also get a few butterworts like I did. It’s an excuse to get another plant and is effective and trapping gnats 😆
Good luck!
Remove top two inches of soil, replace with perlite. Food grade diatomaceous earth sprinkled on top, don’t breathe the powder in. Yellow stickies and DE will rid the adult gnats while the perlite would prevent egg nesting.
Mosquito bits/dunks or sf nematodes will do the trick, then more water less frequently, allowing for bigger dry backs to help keep them from returning. They usually show up in new soil though so be ready to treat for them whenever you bring new soil into your house.
Fungus gnats = wet soil, not light. Let pots dry wayyy more (esp. that portulacaria), add yellow traps for adults, then drench soil with BTI/Mosquito Bits weekly for 34 weeks. Quarantine the worst ones.
I hate the yellow sticky traps, so I have the blue light traps plugged into outlets near my plants. I add Gnatrol to the water for all my plants except the carnivores, who take care of their own gnats.
If anyone is totally gnat-free I want to hear about it, but I feel like I have it under control to an acceptable level. I see them but they are not very noticeable.
I had an absolute mare with fungus gnats! I was very kindly given a huge monstera but it was riddled and got all my other plants. I bought the following:
https://amzn.eu/d/bYrucbE (baby bio houseplant bug killer ultra)
https://www.diy.com/departments/lava-lite-no-gnats-natural-house-plant-fungus-gnat-control-child-pet-safe-1l/0652217571097_BQ.prd (lava lite no gnats granules)
And put decorative stones over the soil of all the plants. I sprayed the plants every other day for a week, and the added a spray to the watering can every time I watered. Did win the war.
Diatomaceous earth and those sticky things you have is what got rid of them for me. But mostly the DE. Also, less frequent watering. That jade plant prefers dry soil and will get root rot if it stays wet.