Bev, the container is about 6" tall or a little more. I used a standard gallon size nursery pot, the ones here they call squat pots because they are the shorter ones, but still a standard gallon. I wanted the container to be smaller at the top than bottom, and knew there was no way I could get a container like that out of the form, so I cut the container on two opposing sides and taped it up with duct tape, making it smaller at the top. That way it was easy to remove my container from the form just by removing the tape.
