What brand of potting mix do you prefer to use or do you make your own potting mix?
I used Miracle Grow potting mix last year, and I ended up with a fungus gnat infestation! I was under the impression that potting mix is sterilized during manufacturing, but I guess it doesn't stay sterile.

The Miracle Grow potting mix was also very powdery, and turned into a hard brick over the winter which was difficult to wet if I let it dry out too much when trying to control the fungus gnats.