sidewalk garden

I've been rooting succulent starts for the sidewalk garden like the fella in the top picture. I cut a few, put them in rooting hormone and then dirt while others seem to root faster in water. I toted a few over on a little foam tray (we use these as paint trays in art class) and then just keep wedging them in to fill in empty spots. This little garden has hit a growth spurt over the last few months.