Astrophytum Myriostigma “Fred” 4”

Astrophytum myriostigma, commonly called bishop’s cap cactus, is a spineless cactus native to Mexico known for its star-shaped body with distinct ribs and a smooth surface covered in fine white speckling. What makes this plant special is its clean, geometric form—typically 4–5 ribs creating a perfect star shape—paired with that dusted, almost frosted appearance that gives it a refined, sculptural look.

Light drives how symmetrical and compact the body stays. Place it in a south or west-facing window where it receives strong, direct light, but introduce it gradually to avoid stress. Under grow lights, use 5000K–6500K placed 6–10 inches from the top of the plant. In lower light, it can elongate and lose its crisp, star-like shape. Strong, even light keeps it compact, flat-sided, and evenly formed.

Watering should be minimal and very controlled. Allow the soil to dry out completely between waterings, then water thoroughly and let it dry again, using a fast-draining mix of succulent soil, perlite, and orchid bark. This plant shows stress through its structure—if it starts to elongate or lose its defined ribs, it’s a light issue. If the base softens or turns dark, the roots are staying too wet. Slight wrinkling while remaining firm indicates it’s ready for water, while any mushy areas signal excess moisture.