As far as pests go, fungus gnats aren’t that bad, but they’re still a problem. These tiny flies buzz around overwatered houseplants, and their presence is a sign of trouble ahead. All is not lost, and you can potentially save a plant after an infestation. Here’s how to get rid of fungus gnats and save your plants.

What are Fungus Gnats?

Fungus gnats are small flying insects and they only live for about 10 days. Adult fungus gnats are irritating and may fly around your face, but they do no harm to houseplants.

An adult can lay 200 to 300 eggs, and their preferred spot to lay eggs is damp soil. The larvae that hatch from those eggs feed on fungus. The organic content in rich potting soil will grow fungus when the soil is kept too damp for too long, attracting gnats. Plant roots will also rot in overly wet soil, creating fungus. Immature fungus gnats cause harm to houseplants by eating the roots.

For what it’s worth, young gnats chewing on the roots is bad news, but these pests only appear if the soil is consistently saturated. Overwatering a plant is equally damaging and would also kill the plant if the fungus gnats never showed up and contributed to the downfall.

Tips to Get Rid of Fungus Gnats

Each case is unique, so consider these approaches and do what you think will work best for your plant.

Dial in Your Watering Routine

Let the potting mix reach the appropriate dryness level, and only water it when the plant is thirsty. Plants have different water needs, so get to know your plant. Prevention is easier than killing fungus gnats.

Set Sticky Traps

There are lots of varieties of sticky traps available that catch mature gnats as they buzz around. While these traps are effective, they only work if the adult gnats fly into them. Keep these traps in place for several weeks, possibly months, to ensure all of the pests are caught. You need to continue to use the traps to catch generations of gnats to fully eliminate the problem. Also, be careful when handling sticky traps to prevent catching your hair or clothing.

Make Your Own Trap Using Apple Cider Vinegar

Fill a small dish with apple cider vinegar and set it near the infested plant. Cover the container with plastic wrap and poke holes in the plastic, so the gnats can enter and drown before they can figure out how to slip away. This method is effective because the smell of the apple cider vinegar pulls the gnats in.

This trap also works for fruit flies. There are traps available to purchase for this purpose. You may have more luck searching for fruit fly traps, but it’s the same thing.

Sprinkle Cinnamon on the Soil

Cinnamon has antifungal properties and will kill fungus if applied to damp soil. The spice will not harm your plant. Still wait until the soil is dry before giving the plant more water.

Use a Hydrogen Peroxide Drench

Most of these tips to get rid of fungus gnats are a long game, because you’ll need to kill the adults, wait for the eggs to hatch, kill those adults, and maybe repeat the cycle a few times to clear up everything. Killing the fungus gnat eggs will speed things up. Mix one part hydrogen peroxide to four parts water and pour the mixture on the potting soil. Try to soak all the soil, so the hydrogen peroxide can kill the eggs. Pouring the mixture on one side will not kill eggs on the opposite side, so the goal is to drench everything.

Be careful using a drench if the soil is very wet and the plant is showing severe signs of overwatering. Drenching already saturated soil will kill the gnat eggs, but will continue jeopardizing the plant’s health. Weigh your options and do what you think is best. Maybe consider using a sticky trap to start, and implementing the hydrogen peroxide drench after the soil dries out somewhat.

Repot Your Plant

Repotting an overwatered plant infested with fungus gnats is worth it in some instances. If the plant is showing severe signs of overwatering and there is a cloud of gnats hovering around it, start over with fresh and dry potting mix. Gently shake away as much of the soil from the root ball as possible to remove any eggs in the soil. This used potting soil may contain fungus gnat eggs, so dispose of it accordingly.

Give the plant a few days to acclimate to its new setup before watering, since it was at capacity before the repotting. Follow up with a sticky trap or an apple cider vinegar trap to clear out any gnats resulting from eggs that survived the repotting.

You’ve Got This

Fungus gnats are a reality of owning houseplants, and you will have to deal with these pests at some point. You can try multiple approaches to kill fungus gnats, but whatever you do, be patient. It takes time to wipe them all out.