Let the top 1–2 inches of soil dry out between waterings
Remove any standing water from saucers and trays
Use yellow sticky traps near the plants
Replace the top layer of soil with fresh, dry potting mix
Repot the plant in sterile soil if the infestation is severe
Water with diluted hydrogen peroxide solution
Apply BTI mosquito dunks or granules to the soil
Use neem oil soil drench
Cover the soil surface with sand or fine gravel
Remove decaying leaves and organic debris from the soil
Quarantine infested plants away from healthy plants
Improve airflow around the plants
Use a fan to help keep the soil surface dry
Avoid overwatering
Check new plants for gnats before bringing them indoors