The whole window will have a one foot wide window sill. I will have to show you the place to get a good idea of things. Basil planted in teacups for the kitchen, cheap and pretty teacups planted with fresh herbs on the window sill.
Indoor Tulips - Fill glass container about with glass marbles or decorative rocks. Set tulip bulb on top of marbles or stones; pointed end up, add more marbles or rocks; so bulb is surrounded but not covered. Pour fresh water into the container.