Last updated on January 31st, 2025 at 01:36 pm
How to eliminate gnats from your houseplants. Fungus gnats are a big problem for most people who want indoor plants. In order to eliminate them, we must first find out where they come from.
Where do fungus gnats come from?
Fungus gnats come from moist soil, leaky drain pipes, overripe fruit, and especially around plants that do not drain well. You have undoubtedly seen them circling your potted plants, indoor trash cans, and decaying matter. They are attracted to moist conditions.
The first thing to do is ensure your plant containers are draining well. Check the holes under your pots, are they plugged? If so poke your finger or a pencil to clear the debris in the hole. It’s amazing how many times this little procedure helps alleviate fungus gnats and root rot.
Will insecticides work?
Spraying with an insecticide will work but the problem is the adult gnats have already laid their eggs in the soil or surrounding area. The main problem is that the spray insecticide will kill the flying gnats but not the larvae that are hidden in the soil.
The larvae pupae will develop into an adult in 4 maybe 5 days this means a new swarm of gnats swarming around your houseplants and inside your home. So…your spraying again and killing the newly hatched gnats is good but the cycle repeats itself again, and again.
How to kill gnat larvae in the soil?
You can use a systemic insecticide to target and eliminate the larvae effectively. This type of insecticide works by being absorbed into the plant through the soil. Simply apply the product directly to the soil around your plant, then water thoroughly to help it soak in. As the larvae feed on the plant’s roots, they’ll ingest the chemical, which ultimately kills them.
This method ensures the treatment gets right to the source, minimizing the chance of missing any hidden larvae. It is best to spray once again to remove any gnats that might still be flying around. Bonide systemic control is a good solution to killing gnats in your soil. Ask for it at your nearest neighborhood Garden Store,
Gnats flying around a plant
What about organic products?
Use BTI (Mosquito Bits®) in the soil it is an organic bacteria product that you apply to the soil that will kill these tiny insects. Sticky fly traps will also do the trick for gnats flying around but of course not the larvae in the soil. You can also apply neem oil into the soil to kill the larvae but make sure to dilute the solution at about half the ratio. Here is a great post on how to use these products in your home. Get rid of fungus gnats.
Some folks swear by the following method. Cut pieces of potatoes and place them into your soil this will attract soil gnats larvae into the soil. The gnat larvae will become trapped inside the potato. Check often then remove and throw into a plastic container and toss in the trash. Use double-sided sticky cards to trap and kill flying gnats and other insects.
Clean out the topsoil of your container, and remove old leaves and other debris on top of the soil.
Learn more about insects and diseases on plants.
How to eliminate gnats from your houseplants
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