Mammillaria nivosa Habitat and Ecology: It has been reported from naked limestone rocks. Its habitat quality is expected to be declining due to urban and tourism development. Almost all of the islands where this species occurs are tourist resorts. However, this species also occurs on Mona Island, which is a protected nature reserve, and presumably not affected by development.
Stem: Globose to short cylindrical, dark green to bronze, 8 – 10 cm in diameter. With latex. Parastichy: 8-13, 11-17 and 13-21.
Tubercles: Obtusely conical, laterally compressed. The axil is densely woolly.
Radial spines: 6-13, straight and very sharp bright yellow to dark brown, to 20 mm long.
Central spines: Usually 1, similar to radials.
Flowers: Diurnal 2 cm yellowish. Stigmas yellow.
Blooming season: Early spring.
Fruits: Club shaped, dark red,
Growth rate: It is a relatively rapidly growing and easily flowering speciesthat will make large clumps given the best conditions. Most plants will offset readily, and clumps can be produced in a few years.
Soils: It likes very porous soil with a fair amount of organic matter.
Repotting: Use pot with good drainage.
Watering: Water regularly in summer, but do not overwater (Rot prone), keep dry in winter. However it needs more water than its Mexican relatives and seems to tolerate moisture around the roots somewhat better than most species.
Fertilization: Feed with a high potassium fertilizer in summer.