Answer: Fungus gnats are so annoying! They breed in moist potting soil, so you can break the breeding cycle by allowing the surface of the soil to dry out. If you have plants that need moist soil simply place a quick draining and fast drying layer of gravel or sand on top of the potting soil. This makes an effective barrier and if you use aquarium gravel, you can choose your favorite color. Or, you can temporarily place plastic wrap or foil over the soil surface - anything to keep the adults from laying eggs in the moist soil. You have to be a little patient with this method because you have to wait through the next generation's maturation before they are gone for good. In other words, once the generation now already in the soil become adults and die off without being able to reproduce, there should be no more gnats. To catch the adults that are flying around you can place yellow sticky traps near the plants (or paint index cards bright yellow and smear them with petroleum jelly), or you can place a cup into which you've poured a few inches of vinegar near the plants. The vinegar will attract the gnats and they usually fall in and drown. Another method is to use a product called Gnatrol as a soil drench, another is to use an insecticidal soap as a soil drench. Of course, always follow the label instructions carefully. I hope this helps!
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