Just turn an appropriately sized cheap plastic pot upside down inside the large- and medium-sized pots and pour soil around them. This creates a platform for the next tier and saves money on potting soil.
How to make a modern hypertufa planter to use outdoors in the garden - perfect for succulents! Use concrete ready mix. plus organic matter (for hypertufa):such as peat moss, cocoa husks, wood chips or sawdust