Mammillaria candida - Snowball pincusion

Mammillaria candida, well known among cactus enthusiasts, recently reclassified as Mammilloydia candida, bears the evocative common name of snowball cactus. This small indoor cactus has a charming, neatly globose silhouette, densely covered in white prickles. It is easy to grow on a sunny windowsill or in a conservatory alongside other succulent plants from dry climates. A pretty crown of pink flowers enhances the appeal of this little plant.

Belonging to the Cactaceae family, this botanical species is native to north-eastern Mexico, where it grows in desert environments or dry scrub, on limestone rocks, in crevices, on rocky slopes, plateaus and canyon walls.
With slow growth, it first forms a solitary, globose stem that becomes slightly cylindrical with age, then it may produce a few offshoots to form a small clump. In cultivation, it most often reaches 8 to 15 cm tall and 8 to 15 cm wide, sometimes more in older specimens. The small projections are barely visible and bear a multitude of fine, dense white radial spines, plus a few longer, sometimes brownish central prickles. This covering gives the plant its very uniform, felted white appearance. In spring, or even late winter depending on conditions, small funnel-shaped flowers appear in a crown near the apex, ranging from pale pink to deeper pink, sometimes tinged with white or marked by a darker midrib. Fruits, when they form (rare indoors), are elongated, red and rather insignificant.

Indoors, this Mammillaria candida requires very bright light or even direct sunlight, a dry to slightly humid atmosphere, around 30 to 50% humidity, and temperatures of about 20 to 30°C during the growing season, with a dry winter rest between 8 and 13°C. Its main issues arise from excess water and insufficient light. It adapts easily to a conservatory, near a south- or west-facing window, or a very bright office.

Mammillaria will benefit from a stay outdoors from spring to autumn, placed in the sun and sheltered from excessive rain. Bring it in before the first frosts to overwinter in a bright, dry and cool place, frost-free.

This is a collection plant, placed either alone in a small pot or among a group of succulents. The whiteness of this Mammillaria candida will showcase companion plants such as Haworthia limifolia, the stockier, spotted Gasteria ‘D. Nella’, Echeveria agavoides and Crassula perforata. In a cactus collection, these combinations vary shapes and colours.