This is because the soil in your yard is not considered sterile. In other words, it could be infested by bugs that could threaten your succulent. You've probably seen this dainty evergreen showcasing its thick carpet of rosettes on a well-manicured rock garden. On the rugged outcroppings of the Chihuahuan Tehuacan deserts, the Mexican Snowball's fleshy rosettes stand out. It is possible that the Mexican Snowball's warm origins are responsible for why this succulent is so fond of the sun. The Mexican Snowball prefers a sandy soil mixture.