thank you Valerie! I will do that! Last year I used "Mosquito Bits" stirred into each can of water I used, and I also sprinkled them in and around the plants.
It did not work. It had no appreciable effect on the gnats.
And so, I am most hopeful about the gnatrol. Also, I am starting the plants in my basement, which is currently 57 degrees. I hope the gnats hate that temperature.