Mix one part hydrogen peroxide and four parts water. Use this solution to water your plants. Hydrogen peroxide will kill the gnat larvae without injuring your plant. Keep reapplying weekly until you notice the gnats are gone.
Because fungus gnats thrive in moist conditions, especially where there is an abundance of decaying vegetation and fungi, avoid overwatering and provide good drainage. Allow the surface of container soil to dry between waterings. Clean up standing water, and eliminate any plumbing or irrigation system leaks.
One surefire way to get rid of them is using Vinegar. It is an effective method for controlling gnats in indoor plants. In addition to sticky traps, this is another effective strategy. A simple solution is to fill a shallow basin with vinegar and add a few drops of dish soap. And place it beside your plant.
You just need to use a few drops of dish soap and a table spoon of vinegar for each cup of water. With this these destructive gnats will parish with just a few spritz of your new chemical weapon. The best part is that you don't have to worry about this solution harming your indoor plants.
Vinegar is a contact herbicide, so you can unintentionally kill plants in your garden if you accidentally spray them with vinegar.
Does Cinnamon Keep Fungus Gnats Away? No—but the idea that cinnamon could provide a natural method for controlling fungus gnats has some basis in reality. "Unfortunately, you can't count on cinnamon on or in the potting mix to help control fungus gnats," Hancock says.
With all that in mind, the EPA says that hydrogen peroxide in low doses is indeed safe for plants. The caveat is of course, in the concentration. Too much can damage plants.
Sticky Traps
Flypaper or more modern decorative sticky traps are popular options to catch any fungus gnats buzzing around houseplants and windows. Small yellow sticky traps can be cut and placed on wooden stakes and inserted into pots close to the soil, where adults tend to crawl and fly.
Baking soda seems so innocent — great for delightful cakes and sponges — but it's adept at cleaning out your drains and killing bugs. So, spread baking soda over the potting soil surface with a sieve, then moisten it with a water spray. And within a few days, the soda will penetrate the larvae and kill them.
Fungus Gnat Deterrents
Fast-draining soils with inorganic additives, like perlite, vermiculite, and sand; Inorganic soil covers, like pebbles, coarse sand, chicken grit, or diatomaceous earth (Some swear by the gnat-killing power of diatomaceous earth!); Pyrethrin sprays approved for organic gardening.
For hydrogen peroxide, mix one part 3% hydrogen peroxide with four parts water. Carefully pour this solution onto the top of the soil, ensuring it reaches the root zone. The hydrogen peroxide will help kill the gnat larvae and any eggs in the soil without harming your plant.
A fungus gnat infestation is a common problem that's not likely to go away on its own.
Fill a glass or a bowl with 1 tablespoon of sugar, 2 tablespoons of apple cider vinegar, a half cup of warm water, and about 5 drops of liquid dish soap and stir well. Gnats will be attracted to the sweet sugar and pungent vinegar, but the sticky dish soap will disable them from escaping.
The only way to get rid of gnats without killing them is to repel them with scents they don't like: vinegar, vanilla, pine oil, peppermint, lemon, eucalyptus, and lavender. Even dryer sheets could help. Of course, the first line of duty would be to get rid of the infestation's root cause.
If you're spraying or watering the soil for fungus, eggs or larvae, be certain you really soak the soil. If you have any of these problems, you can use hydrogen peroxide on your plants once a week.
Prevent Fungal Disease
MAKE IT: Mix 1 teaspoon of baking soda and 2-3 drops of liquid soap in 1 liter of water. Spray the solution on the infected plants. Baking soda helps the plants become less acidic and prevents fungal growth.
To get rid of fungus gnats, mix a solution of one part hydrogen peroxide with four parts water. Pour the mixture onto the soil around the infested plant.
There are almost countless uses for cinnamon in the garden: it can be used as a nature-friendly pesticide, a repellent against annoying insects, or as a catalyst to promote root growth in plant cuttings.
Homemade gnat repellent spray: A mixture of dish soap, water, baking soda, and vinegar can be filled into a spray bottle. The mixture should contain a few drops of dish soap, a tablespoon of vinegar, and baking soda per cup of water. A few sprays of this mixture is an effective gnat repellent.
Place a bowl near the infestation and fill it with vinegar before adding a teaspoon of plain sugar, which is what the gnats will be drawn to. The vinegar is what will ultimately kill them, but you also need a way to keep them in the bowl long enough for that to happen.
One of the single best uses for unfinished opened beer is as a compost pile jump starter. The sugars and yeast in beer are excellent for your compost pile. Simply pour it over your compost pile and then stir or turn it when required. Beer can be used as an effective fungicide for your plants.
Vinegar is a contact herbicide, which means it kills the part of the plant it comes into contact with. Systemic herbicides, on the other hand, are taken up by the plant's vascular system and delivered to roots, eventually killing the whole plant instead of just its top growth.
Simply mix 2 tablespoons of hot pepper sauce, a few drops of biodegradable dish soap and 1 quart (0.94 liters) of water and let it sit overnight. Use a spray bottle to apply the spray to infested plants.