It doesn't matter what brand of multi-use I buy, I get tiny black flies which seem to live in the soil. I have herbs along my kitchen windows which are infested. What can I do to stop this happening?
Tiny Black Flies in Multi-Use Soil
Certified GKH Gardening Expert
It sounds like you have fungus gnats. This article will help: https://www.gardeningknowhow.com/special/children/fungus-gnats.htm
Neem oil will help take care of these pests but will not hurt the plants. Here is more information: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm