I had the same problem this winter. And mine came out of a bag of brand name: potting soil. I bought a bottle of organic pest spray from my local nursery and it has helped a lot. Surprisingly, I thought these were fungus gnats, but I repotted a bunch of the plants, and there was no damage to the roots and there were no littlelarva or anything in there like it talks about on the web. The thing that helped the most was putting up a bunch of those sticky strips.I also found making a mixture of a little bit of sugar and soap in water and pouring it into a yellow dish or lid has worked beautifully. They are attracted to yellow, and they get in there and they drown. I have several dishes of that sitting around and I keep it filled up.
