Hi! I have many house plants all in my room bc I’m a college student sharing space with my roommates, they get about 3-4 house of bright light, plus I turn on supplemental plant lights every day for at least 3-4 more hours. When I moved in my plants developed fungus gnats. At first I isolated the infected plants and went on with my life, trying to reduce watering and adding yellow sticky traps to the pots. The infestation got worse and now it’s out of control. I’ve tried gnat death drops, yellow sticky traps, drying them out, adding perlite to the soil and on top, even repotting almost every single plant and nothing is working. I’ve read about nematodes but I don’t think I would be comfortable trying those in my carpeted room. Using the bti gnat drops consistently meant watering my plants way too much so now I’m gonna try just drying them out and using a bunch of the yellow sticky traps. Does anyone have any advice?
by OnionAffectionate362
10 Comments
Looks like you have a lot plants that would be good candidates to transition to semi hydroponics. Converting half my plants to semihydro has significantly decreased my fungus gnat issue problem. You literally eliminate their habitat so it is far better than the mosquito bit tea solution.
When I was dealing with fungus gnats, I was told that I had to drench the roots with BTI-treated water every 7-10 days. I didn’t follow this and only watered when the plants actually needed water. It seemed counter-intuitive to me that I was overwatering my plants which leads to root rot, which then attracts fungus gnats. I also brought a Zevo trap which helped in my experience. Don’t lose hope! Sometimes, it just also seems like it gets worse before it gets better. Treatment will take time.
Bonide insecticidal soap spray. Spray down the soil nightly. After a week, they get a thorough drench. Do it again for a week. I also added sundews (drosera binata), they were very well fed.
I let my soil completely dry out then drown it with a 4:1 water to hydrogen peroxide mix and that took care of it. After that I only bottom water, they are more likely to come back with top watering
I got one of those Zevo lights and it’s seemed to help as well, away from the plants
I’m having a problem with those myself
Not saying this is a good practice (and I probably wouldn’t do it for smaller/younger plants), but it worked for me when I was at my wits end with fungus gnats.
I took all my plants out of their pots, hosed down the roots until there was almost no dirt left, hosed down the leaves and stem as well. Then I repotted them in fresh soil (NOT Miracle Gro)
Also not sure if you have anywhere to do that since you’re in a dorm 🤷
Beneficial nematodes solved my fungus gnat issues. I use them 3-4x a year as a preventative now.
I’ve had good luck using mosquito bits. I take a spray bottle and put some in a tea bag and make anti bug tea. I spray the soil with it every few waterings neem oil/meal is also an option
Diatomaceous earth on the top and mixed into the soil a bit has worked for me in the past. The biggest issue is that you have to treat every single plant at the same time, otherwise they move on to the next plant.
I’ve used nematodes too.