How can I safely get rid of fungus gnats from my potted hydrangea?
Fungus Gnats are harmless but irritating. They are attracted to organic material in the soil and often lay their eggs there. Keeping the soil on the dry side will help eliminate them. There is a biological control called Gnat Off. You can use any houseplant insecticide including insecticidal soap and drench the soil, then let the soil dry somewhat. It won't harm the plant.