How To Get Rid of Gnats in Plants Naturally: Homemade Gnat Repellent

What Are Fungus Gnats?

Fungus Gnats are tiny flies that live and reproduce in moist, nutrient-rich soil.¹ They look like really tiny mosquitos and are about a quarter of an inch in length or smaller, with a dark skinny body and small clear wings.

They are not strong fliers, so they tend to stay within a few feet of plants.

What Is The Life Cycle of Fungus Gnats?

Fungus Gnats lay eggs in the soil, which hatch in about 4 to 6 days. The larvae feed on the roots and nutrients in the soil over the next 2 weeks.

It then enters the pupal stage for about 5 days before transforming into an adult insect with wings.

Fungus Gnats only live for about 8 to 10 days, but during this time they can lay up to 200 eggs.

The short life cycle of Fungus Gnats helps make them easier to control.

How Do I Know If I Have Fungus Gnats?

If you notice small flying insects flying around your houseplants, usually within just a few feet of the plant and staying close to the soil, you have Fungus Gnats.

You can check the soil for fungus gnat larvae by looking very closely at it and watching for almost undetectably small whitish-silvery almost transparent lines moving around.

They will be about an eighth of an inch long. The larvae will grow into the adult Fungus Gnats in about 2 weeks.

Are Fungus Gnats the Same Thing as Plant Flies?

The term “plant flies” is just another name for Fungus Gnats. Both names refer to the same insect.

But, however you label them, they can be a serious issue.

Are Fungus Gnats Harmful To Plants?

Fungus Gnats are harmful to your plants in a few different ways.

First, they eat the nutrients out of the soil. These are the same nutrients your plants need to grow and stay healthy.

Fungus Gnats also eat thin root hairs on your plants, which further decreases their ability to get nutrients. This is why you’ll see plants with fungus gnat infestations having stunted and slowed growth, and leaves that yellow and fall off.

Younger plants are also more susceptible to damage and even death from fungus gnat infestations as they are less resilient than older, more established plants.

If left untreated, Fungus Gnats can eventually kill your plant. However, this is an extreme outcome, and with just some simple treatment steps you can get rid of Fungus Gnats and the damage they cause.

Are Fungus Gnats Harmful To People?

Fungus Gnats are not harmful to people.

They do not bite or carry any infections or diseases that will affect humans or pets.

What Causes Gnats in Plants?

The biggest cause of Fungus Gnats in plants is overwatering.²

Fungus Gnats need moist soil to lay their eggs in, so soil that is consistently very moist will attract Fungus Gnats from the environment and cause them to infest the plant.

Why Do I Have Gnats in My House?

Fungus Gnats can enter your home through screen windows, and doorways, and anyway any other insect can enter.

But it’s overly and consistently moist soil that makes them stay and start causing problems for your plants.

As long as your houseplants have overly watered soil, it will be an attractive environment to Gnats and a cause of them entering your home.

Will Fungus Gnats Go Away on Their Own?

If you’re hoping that learning how to get rid of fungus gnats can happen on it’s own, sadly no.

These pesky insects will not go away on their own without you changing some of your plant care habits. If whatever conditions attracted them are still going on, they will continue to multiply and thrive.

You can take simple steps like letting the soil dry out and using traps, but you will need to take action to make the Fungus Gnats go away.

How To Get Rid Of Gnats In Plants Naturally

There are a number of things you can do to control and ultimately eliminate Fungus Gnats.³

Here are some simple, toxin-free, and cheap ways to get rid of Gnats in plants naturally.

Let the Soil Dry Out

Fungus Gnats lay their eggs in the top inch or so of the soil, and it needs to be moist for eggs to survive. Larvae also need moist soil to survive.

If you let the soil try out, existing eggs and larvae will die, and no new eggs can be laid.

Don’t water your plants if the top few inches have any sign of moisture. Let them completely dry out.

Use Hydrogen Peroxide To Kill Larvae and Eggs

When considering how to get rid of fungus gnats, take steps before you water your plants again, and make a mixture of about 20 to 25% hydrogen peroxide and 75 to 80% water.

You can use standard 3% hydrogen peroxide.

Hydrogen peroxide will kill both eggs and larvae without harming your plant at all.

Repeat this weekly until the Gnats are gone.

Vinegar Traps

Another way how to get rid of Gnats in plants is to make a trap for fungus gnats by taking a cup or bowl and pouring in some apple cider vinegar and a few drops of dish soap.

Cover the top with tape, sticky-side down. Poke some small holes into the tape so the fungus gnats can get into the trap.

The Fungus Gnats will be attracted to the vinegar. When they land in it, the dish soap will cause them to become stuck in the trap. The tape will help make sure that once inside the trap, the Gnats won’t be getting back out.

Set these traps up within a foot of your infested plants. You can change the trap liquid and tape as desired or when full.

Sticky Paper Traps

You can buy sticky paper traps to catch adult Fungus Gnats as they fly around your plants. These traps are small plastic stakes with sticky adhesive on both sides. You simply stake them in your plants, and the yellow color you’ll typically find them in is supposed to attract the Gnats, who then get stuck in the adhesive.

This helps control the population of adult, egg-laying Fungus Gnats while also helping you monitor the level of the infestation.

You can find them in cute shapes like butterflies and suns, so they won’t look too unsightly in your plant collection.

Potato Traps

Fungus Gnat larvae are attracted to potatoes, so this is an easy way to lure and trap them.

Take a raw potato and slice it up. Place the slices on the soil, and the larvae will start to feed on it instead of your plant’s roots or soil nutrients. Within 24 hours, check the slices and dispose of any that have small larvae feeding on them. Replace and repeat until the situation is under control.

Don’t let the potatoes dry out or the larvae won’t be attracted to the slices.

How To Use a Fruit Fly Trap for Fungus Gnats (How To Get Rid of Gnats in Plants)

You can use a fruit fly trap for Fungus Gnats by setting the trap up within about a foot of the infested plants.

(Image: Mike Pennington⁴)

Since Fungus Gnats aren’t good at flying, they will stay close to the plants they live in. Setting the fruit fly trap up anywhere else won’t be effective against Fungus Gnats.

What Is an Effective Gnat Repellent?

The most effective Gnat repellent for how to get rid of Gnats in plants is good plant watering habits.

Make sure you are allowing the top few inches of soil to dry out between waterings. When you water plants, don’t overwater them.

Choose pots that allow the soil to get good airflow like clay pots, or ones with drainage holes in the bottoms.

Remember, Fungus Gnats can’t reproduce in soil that isn’t moist. And they aren’t attracted to environments that are dry.

What Are the Best Methods of Pest Control for Gnats?

The best methods of pest control for Gnats are:

• Allowing soil to dry out between waterings and not overwatering
• Choosing pots with good drainage
• A 25% to 75% hydrogen peroxide to water mixture
• Vinegar traps
• Sticky paper traps
• Potato traps

Do I Need a Gnat Exterminator?

You don’t need a gnat exterminator to get rid of Fungus Gnats in your houseplants.

It may take a month or so of regular efforts such as watering with a hydrogen peroxide and water mixture and changing out traps, but a Fungus Gnat infestation is manageable without an exterminator.

When To Call an Exterminator for Gnats (How To Get Rid of Gnats in Plants)

If you’ve tried everything and still can’t seem to manage the fungal gnat issue in your plants and you are unable to know how to get rid of Gnats in plants, you can consider seeking professional help from an exterminator.

Just be aware that the methods they use will likely involve pesticides that can pose threats to animals or children.

With some time, effort, and attention, you’ll know how to get rid of Gnats in plants naturally and prevent future infestations quite easily.