The children in the lower grades at our school are starting geraniums from cuttings (mostly mine). What is the best planting medium to use? This needs to be nearly no cost solution...or very little cost. These plants usually wind up being a Mothers' Day gift. This is for grades K through 6. We have such a small population that these grades are in two rooms!! A volunteer helps the children in the school green house. Any and all information to make it the easiest for these little ones is appreciated. Thanks so much..........Diane