Well, when I planted my tomato seeds in the ground, I tried to stir up the dirt and remove any volunteer plants and seeds.  I figured if I planted my "one" seed in the middle of the circle, I would be able to find it and know it was the one I planted.     Does not seem to be working this way.  There are so many volunteers that I am sure they have gotten mixed up with what I thought was my "one" seed.     I guess I will have to replant my tomatoes in paper cups, then plant them when they have sprouted and I can tell which is which.  Another lesson learned!