Greetings from the Lithops world. We may seem like simple stones, but our survival depends entirely on the foundation you provide for our roots. Getting the potting mix right is not a matter of preference for us; it is a matter of life and death. Our native habitat is the harsh, arid, and incredibly well-draining quartz fields and rocky slopes of Southern Africa. To thrive in an American home, you must replicate these conditions in a pot.
Our greatest fear is wet feet. Our roots are designed to seek out moisture quickly and then dry out entirely. A standard potting soil, which is rich in organic matter like peat moss, acts like a sponge. It retains water for far too long, surrounding our delicate taproot and stem body in constant moisture. This leads to certain and rapid rot, a death sentence from which we cannot recover. The mix must be predominantly (80-90%) inorganic, gritty materials that provide structure, weight, and instant drainage, preventing any water from pooling around our core.
Think mineral, not organic. A perfect mix for us mimics our native gritty desert floors. The base should be a coarse, sharp material like poultry grit, pumice, or perlite. These components create essential air pockets and ensure water flows straight through. To this, add a smaller portion of coarse sand (horticultural sand, not fine play sand which compacts) and optionally, a handful of small lava rock or baked clay chips (like Turface). The minimal organic component, if any, should be a very small amount of sifted coconut coir or pine bark fines (less than 10-20%), solely to offer a minuscule amount of moisture retention for the roots to absorb. The final texture should be loose, gritty, and unable to hold its shape if you squeeze a handful.
Please, avoid anything that promotes water retention. This includes standard potting soil, garden soil, compost, sphagnum peat moss (unless used extremely sparingly), and any moisture-retaining crystals. These materials are a death trap for us. They compact over time, suffocating our roots and creating a constantly damp environment that invites fungal rot. A mix that feels like dirt is a mix that will kill us.
The perfect soil mix is only half the solution. Its partner is an appropriate pot. We require a pot with exceptionally large drainage holes. Terracotta pots are highly recommended because the porous clay walls allow for evaporation from the sides as well as the top, helping the soil dry out much faster than a plastic or glazed ceramic pot. The pot should be deep enough to accommodate our long taproot, typically at least 3-4 inches deep, but not excessively wide, as this increases the volume of soil that stays wet for longer.
