Best Gnat Killer For Indoor Plants. Dissolve 3 tablespoons of sugar in 1/4 cup of vinegar and pour it into the bottle. Fungus gnats love wet soil, so you want to make sure the top one to two inches of soil are dry before watering again.
Spray bottle ( purchase here) ½ cup of water. 10 insecticide to kill gnats review: Research the characteristics of the best gnat killer for indoor plants.
