Put the amount of soil you desire in the glass jar, then you evenly strew the seeds and cover it with an extra half a centimeter of soil. Finally put the jars in a window and spray them with water as often as necessary to keep them moist
It took us fore to five days to get the grass this high, a nice little terrarium project.
Glass jars (once we have nice ones in the fridge and we are finished with the content, I always wash and keep)
Water sprayer and finally