Hi there, I just recently noticed fungal gnats in my medinilla magnifica plant's soil and so I let the soil dry out. Then I read about using hydrogen peroxide to get rid of these pests and tried it. Unfortunately, I used too much I think. I used about a quarter of a cup of HP and a cup of water. Will my plant die? Is there a way to fix this?? Thanks!
Too Much Hydrogen Peroxide!
Certified GKH Gardening Expert
It will help me to see the damage. Usually, peroxide will not cause this kind of damage at that strength. This was regular 3% wasn't it? These gnats are actually very beneficial to your plant. They eat, only, rotting material in the soil. If there were so many that you began noticing them, then this is a sign that the plant was already suffering from an infection in the roots. They will only usually fly around if the soil remains too wet for long.
It is quite possible that they were keeping an infection at bay from overwatering, and removing them allowed the infection to take over. The peroxide should help this recover. Just make sure to let the soil dry out on top before watering. This will keep the gnats in check as well.