Huernias require a potting mix with excellent drainage. A succulent plant mix of 50 percent pumice or perlite, 25 percent peat or organic mulch, and 25 percent sand helps prevent rotting and overwatering.
Roots experience dieback in cool-season dormancy, so plants grow best in shallow containers that allow the soil to dry out quickly. Clay pots further help soil from staying too wet.
An underlayment of coarse gravel below the soil mix also improves drainage. In climates with damp cool summers, a layer of gravel between the plant and the soil mix also helps prevent the stems from staying too moist.
Outdoor plantings do well in raised beds. Huernias prefer bright light or partial shade. In nature, they grow underneath shrubs or other plants. Too much sun causes stems to develop protective reddish or purple pigmentation and can actually scald the stems.
Too little light leads to weak, thin growth with decreased flower production.