These pests are entirely uncool and could cost you your plants if not treated speedily and properly. I learned the hard way with fungus gnats when I first started as a newbie gardener — and it did cost me my plants, boy was that disappointing!
Luckily, I learned from that experience and ever since, I lead an arsenal of preventative tactics to avert a gnat crisis from ever happening again. I’ll be sharing with you some techniques that work — ones I have personally used, so you can get your arsenal amped for some fungus gnat take-down.
What are fungus gnats?
At first, I mistook fungus gnats, thinking they were a typical fruit fly or drain fly, but they are totally different. Fungus gnats are comprised of many different families (I won’t get into the scientific names here), but they all go about business the same way. What business might that be? They enjoy damp soil and feed on fungus within the soil, decayed leaves and plant roots.
What does that mean for my plants?
It depends. Healthy plants are usually not prime real estate for fungus gnats. Typically, fungus gnats go for seedlings and plants that have been overwatered or immersed in water for too long. They enjoy the fungus within soil, so if your topsoil is saturated and contains yummy fungus, that could be a target as well.
Fungus gnats carry disease such as the pathogen responsible for damping-off disease. This is a fatal disease that hits seedlings and young plants. If your seedlings fail to rise, if they look weak, stringy, or feel watery-like, chances are it is damping-off disease. If your tray of plants also has fungus gnats — therein lies the most likely culprit.
How do I get rid of them?!
The good thing is there are many natural approaches to ridding fungus gnats that really do work. There are also commercial level insecticides available, but this article is focused on removal around the household in the safest possible manner.
- Let affected soil dry out. This can be tolerable for some plants such as succulents as they require very little water. Plants such as ferns always require evenly moist soil. This is a challenge, as attempting to rid the gnats could dehydrate your plant to death. If your plant can tolerate dry soil, then let it dry out. No moisture = unhappy gnats.
- Purchase goGnats liquid concentrate. This is mixed into water, for best results I recommend using a fertilizer sprayer to evenly coat your plants (if you have more than one plant affected and as a preventative measure). This is a poison-free approach that works, using cedar oil as a gnat deterrent.
- Throw your plants out. No just kidding — don’t do that!
- Purchase Gnat Nix! fungus gnat control. Gnat Nix! is a non-toxic solution that deters fungus gnats at all life-cycle stages through a specifically formulated top dressing. This top dressing should be coated at all times around your plant and it will work wonders!
- Purchase Yellow Sticky Traps. Yellow sticky traps might not look pretty but gnats are attracted to the color yellow and is a good alternative to insecticides.
- Live nematodes. These are live organisms that penetrate within the soil to kill off gnat larvae. Nematodes will also rid off other insects as well such as fleas, termites and grubs. It’s easy to use, especially when used in a pressure sprayer. Another bonus is that nematodes work well with other beneficial insects such as ladybugs and earthworms.
Hopefully some of these tips can remedy your gnat problem. Sometimes it might be more helpful to use more than one method in order to clean up the problem quicker. Maybe you bought contaminated soil which might affect plants used with that soil, but that also creates a window for gnats to infest other, healthy plants, and you do not want that happening. Post in the comments below any additional methods you might have found useful!