Get Rid of Decaying Matter Clear your plants and soil of decaying leaves, flowers, or organic matter. Remove dead flowers, leaves, or other plant parts from your plants. You should also check any fruits that are out for overripeness; gnats are attracted to ripe fruits or ones that have begun to ferment.
One of the easiest ways to control them is to place a barrier between moist potting soil and the little pests. You can simply cover the soil with aluminum foil or plastic wrap, or cover the top of the soil with pea gravel or decorative rock such as those used in aquariums.
Gnats are attracted to the moisture in the soil, which is why you often see them near potted plants or indoor gardens. While they don't feed on the plants themselves, they lay their eggs in the soil. The larvae that hatch from these eggs feed on plant roots, causing extensive damage.
Ground coffee is not effective against gnats in plants. However, coffee grounds may make the fungus gnats problem even worse. Placing them on the soil's surface makes a barrier prone to mold growth and attracts fungus gnats. They thrive on decomposing organic debris, and coffee grounds provide plenty of that for them.
Start by bringing them in at night, then move them out during the day. Then leave them in for a day, then two, moving them back outside in between. A big change in climate, light, temperature, and so on can shock a plant, and you want to make sure it stays as healthy as possible to help prevent any bug infestations.
Mix 1 cup of rubbing alcohol with 1 quart (32oz) of water. Pour the solution in the spray bottle or straight rubbing alcohol for thicker, hardier leaves. Step 3: Spray the whole plant, not only where mealybugs are visible.
Some experts recommend bathing or soaking plants in a bucket of water with mild dishwashing soap before bringing them inside. If your plants are too big for the bucket treatment, spray them with water to remove outdoor dust and soft-bodied insects from the leaves.
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.
Opt for used coffee grounds, instead of fresh.
When considering using coffee grounds to fertilize your houseplants, we recommend sticking with used coffee grounds. This is because fresh grounds can be high in acidity and caffeine, which can have a negative impact on your houseplants.
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.
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.
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.
Pair a hydrogen peroxide solution with a powerful spray bottle for the best results. Mixing water and hydrogen peroxide creates a solution that can be sprayed on plants to get rid of gnats without harsh chemicals. The solution helps kill gnat larvae and even deters adult gnats from laying eggs.
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.
A fungus gnat infestation is a common problem that's not likely to go away on its own.
Avoid using coffee grounds on alkaline-loving trees, such as linden, ironwood, red chestnut and arborvitae. Coffee grounds used as mulch or compost inhibit plant growth on geranium, asparagus fern, Chinese mustard and Italian ryegrass. Definitely don't use coffee grounds with these plants.
The idea is simple enough—soak banana peels in water to extract nutrients, and then pour the water into your plants as a kind of fertilizer. This method has gone viral, with the idea being that the nutrients in the banana peels (like potassium and vitamin C) will directly benefit your plants.
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. They may be sprayed in areas where gnats are commonly seen, such as around plants, in the bathrooms, etc.
Summit Mosquito and Gnat Barrier spray contains permethrin, a proven residual insecticide that has been used in mosquito control for many years. In addition to mosquitoes, it also controls a wide variety of outdoor insect pests including ants, fleas, ticks, earwigs, and more.
Repeat this process a couple of times for the best results. Spray with Insecticidal Soap: Before bringing your plants indoors, thoroughly spray their leaves, stems, and trunks with insecticidal soap to eliminate any remaining pests. Allow the spray to dry thoroughly before bringing the plants inside.
If you're wondering how to debug plants before bringing them in the house, look no further than insecticidal soap. It's one of the easiest solutions for debugging houseplants, as well as outdoor garden plants.
Saturate the soil with 1/2 cup hydrogen peroxide 3% per 1 litre water. Put wet soil in a watertight container and leave overnight before planting. This kills pathogens such as fungi and bacteria including insect eggs and nematodes (roundworms).