Are your houseplants suffering from a fungus gnat infestation? Don’t despair! There are easy and natural ways to get rid of fungus gnats in your houseplants. Find out what kills fungus gnats in the soil and what non-toxic ingredients to use like vinegar, neem oil and diotomaceous earth
How to get rid of fungus gnats in plants naturally
House plants have been gaining popularity over the past couple of years and the trend doesn’t seem to be slowing down anytime soon. People are longing for more of a connection with nature and trying to find ways to bring the outdoors inside-especially people who live in apartments or don’t have access to a yard or garden.
One of the worst things a plant owner can find is a fungus gnat infestation on one of your beloved plant babies. Don’t worry, you don’t need to throw your plant out if you find fungus gnats on it. There are steps you can take to kill the fungus gnats and make sure they never come back.
What is a fungus gnat?
Fungus gnats are small, dark, fly-like bugs. The larvae of most gnat species feed on fungi growing on soil. They help the decomposition of organic matter.
Gnats are typically harmless to healthy plants - and humans - but can inflict extensive damage to seedlings and their presence can indicate more serious problems. In houseplants, the presence of gnats may indicate over-watering. Gnats may be feeding on roots that have been immersed in water too long and are thus rotting, or the gnats may be attracted to fungus growing in saturated topsoil.
The first step to killing fungus gnats is making sure your soil doesn't stay too wet. Let it dry out between watering and make sure the planters have adequate drainage holes so that the roots don't sit in water.
What kills fungus gnats in soil?
Commercial greenhouses typically use the insecticide diflubenzuron to control fungus gnats and their larvae. It is applied to infected soil and will kill fungus gnat larvae for 30-60 days from a single application. It works by interfering with chitin production and deposition and it also triggers insect larvae to molt early without a properly formed exoskeleton, resulting in the death of the larvae.
Chances are you don't have a bottle of diflubenzuron in your cupboard to kill fungus gnats. No fear. There are plenty of household products that work really well for getting rid of fungus gnats and that are safe for you, your pets and your kids.
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Supplies you may need to get rid of gnats:
- hydrogen peroxide
- vinegar
- neem oil
- sand
- cinnamon
- Gnat Stix
- Bounce sheets
- diatomaceous earth
How to get rid of fungus gnats with hydrogen peroxide
Hydrogen peroxide makes a great gnat killer. Mix one part 3% hydrogen peroxide with four parts water. Allow the top layer of your soil to dry, and then water your plants with this solution as you normally would. The soil will fizz for a few minutes after application; this is normal. The fungus gnat larvae will die on contact with the hydrogen peroxide.
Is hydrogen peroxide harmful to plants?
The hydrogen peroxide is diluted, so it won't hurt the plants. Just make sure it is diluted at a ratio or 4:1 as per the instructions and it will be fine for your plants.
How do you get rid of gnats in houseplants with Gnat Stix?
If drying out the soil and using peroxide doesn't seem to help in getting rid of gnats in houseplants, you might try a product like Gnat Stix, which are yellow sticky traps. Place the trap near your plants to catch the adults and thereby reduce the number of eggs the fungus gnats lay.
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Does neem oil kill fungus gnats?
Neem oil is also an effective organic control for fungus gnats and can be used as a soil drench to kill the larvae. Neem oil might kill some plants, especially if they are young and if the oil is applied too heavily. Test a small area of the plant and wait 24 hours before applying it all over. Apply neem out of direct sunlight for indoor plants to prevent leaf burning.
Neem oil won't kill all of the pests on contact, so it might take a few days, weeks or even months for all of the bugs to disappear from the plant.
You may also like: The Ultimate Houseplant Care Guide
Diotomaceous earth for fungus gnats
Food grade diatomaceous earth is another effective treatment for fungus gnats. Mix some into the top layer of infested soil, or better yet, into your potting mix before planting and it will kill any gnat larvae (and adults) that come in contact with it as if they were crawling through crushed glass.
How do you apply diatomaceous earth to potted plants?
Wet method of Diatomaceous Earth application:
- Add 4 tablespoons of diatomaceous earth into a one-gallon container of water with a lid the seals tightly.
- Shake until combined.
- Fill a spray bottle or garden pump sprayer with the mixture.
- Spray the plants with a fine mist until they are wet but not dripping.
- Allow the plants to dry.
Other home remedies
For years, gardeners have claimed that putting Bounce fabric softener sheets in their pockets is an effective way to repel pests like mosquitoes and gnats. Any Internet search will uncover countless articles about the bug-repelling properties of Bounce. Are these claims valid or simply folklore?
The authors of a new study say that until now, no quantitative data has existed to substantiate these claims, but their latest research has revealed a definitive answer: Bounce® sheets do indeed repel adult gnats.
I would use the dryer sheets as a deterrent rather than a treatment for fungus gnats. If you don't have an infestation but it's something you are worried about happening in the future, tuck a few dryer sheets between and underneath your plants.
Yes! This is another treatment that will work better as a deterrent that actually killing the gnats. Simply sprinkle enough cinnamon to form a visible layer across the top of your potting media, and repeat every few weeks, if needed.
Addding a half-inch layer of sand on top of the potting soil in each pot can keep fungus gnats from breeding. It works because sand drains and dries quickly, denying the fungus gnats the moist soil they prefer.
Another household ingredient that can be used to get rid of gnats in houseplants is vinegar. Every other time you water, add one tablespoon of liquid dish soap and one teaspoon of white vinegar to the water. Eventually it will kill the fungus gnat larvae.
How do you get rid of fungus gnats in your houseplants? Let me know your best tips and tricks in the comments.
Hi I’m Adrienne Carrie Hubbard. I believe a rich life comes not from the things you have, but the things you do; the experiences you create and the people you meet along the way. Thanks for hanging out!