The adult gnats can be removed with a vacuum cleaner from windows and from around the plants. Watering plants only when they need water will help prevent fungus gnat infestations. Fruit. For most gnat populations, their food source must be located and corrected if possible.
Complete Fungus Gnat Prevention Strategy. Here's your step-by-step plan to eliminate fungus gnats and prevent their return: Immediate Action (Week 1). Apply diatomaceous earth to soil surface and spray solution on foliage.

As we can see from the illustration, Water Quality And Gnat Prevention has many fascinating aspects to explore.
Gnats love Standing water Water that collects in drains, trays, or leaks can create ideal breeding conditions. Even a small amount of organic material can support a gnat population, which is why infestations often appear suddenly.

Our Expert Agrees: Gnats are attracted to oversaturated soil; let the soil in your potted plants dry out completely before watering them again. You can also scoop off the top inch of soil. Doing this, you'll notice that your gnat population will decrease after a couple of weeks.