Like mushrooms, fungus gnats love damp soil. So much so, they lay their eggs in it which only increases the problem. And just like ridding our soil of mushrooms, we need to reduce our watering as we transition from the warmer summer months to the cooler fall and winter months. The best cultural practice is to water your plants from the bottom, limiting the amount of moisture at the surface of the soil. By doing so, the top 1-2 inches of soil will be dry enough so the gnat larvae die and interrupt the life cycle. This is easily accomplished by putting your plant in a 2 inch deep dish or saucer, filling the saucer with water and allowing the soil to absorb the water like a sponge through the holes in the bottom of the pot (make sure you have holes in the bottom of your pot!). Water in this manner instead of watering the plant from the top like we all normally water. Over time, the fungal gnats will disappear. An alternative solution, if you’re not able to water from below, would be to put a one inch layer of sand or fine decorative rock on the top of the soil to limit the fungal gnat access to the soil surface.