I repotted my overgrown pothos and bought dirt from home depot for it. The dirt seemed to be majorly infested with gnats :/ i’ve been letting it dry out a little, spraying it with neem oil, and have a fly trap but it definitely needs a better solution. Any recommendations?
by Cr_noeller
10 Comments
Water + a few drops of dish soap in your next watering
If you’re in the US get some mosquito dunks or mosquito bits. Follow the directions to add to your water when you water them for a few weeks. The bits will kill the fungus that the gnat larvae feed on thus ending their life cycle and it doesn’t harm the plants at all. You can even use them sporadically as a preventative when you don’t have a problem. I mentioned the US by the way because it’s my understanding this product isn’t available everywhere. This process works to eliminate even the largest infestations in a few weeks to a month.
Fungus gnat nematodes sorted the problem out for me. Make sure to treat all your plants though to make sure they don’t survive somewhere else and spread again.
Pothos can handle dry soil better than fungus gnats. Let the soil get absolutely bone dry, wait a week, then water. That should reduce their numbers dramatically. Do that every time you water until they’re gone
Put sand on top of the dirt (~2cm at least). So the gnats can’t come out.
Got rid of them that way. Neem oil didn’t help that much
Get a pinguicula plant and watch the massacre
You are probably overwatering and your soil is likely low quality with poor drainage.
To get rid of them now, water with once with arbor insecticide, which will inoculate the soil with bacteria that kill fungus gnats. Let the plant dry out more between waterings. Underwatering is better than overwatering for pothos.
Longer term, you want to repot the plant into soil with better drainage in a smaller pot that dries out more quickly. Your plant will do better in this type of soil and you can water more frequently without worrying about overwatering. Easiest way to do this is mixing orchid or cactus mix with potting soil.
you need diatomaceous earth – i had a bad gnat problem as well, i sprinkled some of this on top of all my potted plants and after a short while they were all gone!
I’ve been through all the ways of dealing with this. You can try dunks, they seem to help a bit but to eradicate an issue I suggest lost coast plant therapy. Food grade but it is a drying agent so so kist with a mask. That and beneficial insect soil do the trick. I spray the surface of all my plants once a week. Maintainance pretty much guarantees you’ll never have a crisis. This is typically called IPM.
Thanks for the tip! Time to declare war on the gnat army!