Noun
potting soil (countable and uncountable, plural potting soils)
A substrate used to grow plants in containers, made from various substances that promote moisture, drainage, and fertility.
Synonyms: growing media, potting mix, potting compost
Secrecy is the potting soil in which all this conspiracy shit grows. Trust me. The roaches don't like it when you start shining a light on them. Daniel Abraham