Pack Size: 20, 100, 300
Year: 2026
Accepted Scientific Name: Mammillaria hahniana Werderm.
Common Name: Old Lady Cactus
Origin and Habitat:
Mammillaria hahniana is native to central Mexico, particularly the states of Guanajuato and Querétaro. It inhabits rocky hillsides, limestone slopes, and dry scrublands, growing in shallow, well-drained soils among rocks and sparse vegetation. These environments experience warm summers, cooler winters, and seasonal rainfall followed by extended dry periods. The species is adapted to exposed conditions and develops a dense covering of long, white, hair-like spines that helps protect its green body from intense sunlight.
Description:
Mammillaria hahniana, commonly known as the Old Lady Cactus, is a highly ornamental species forming rounded to short cylindrical stems approximately 4–10" tall and 4–6" in diameter. The green body is densely covered with numerous white radial spines and long, silky white hairs, creating a distinctive woolly appearance. Older plants may produce offsets and gradually form attractive clusters. Mature specimens produce brilliant pink to reddish-purple flowers arranged in a ring around the crown during spring and summer. Its dense white hairs and vibrant flowers make it one of the most recognizable Mammillaria species.
Cultivation:
Zone: 9–11; protect from prolonged frost and winter moisture.
Temperature: Optimal growth at 18–28 °C. Maintain winter temperatures above 5 °C.
Growth Rate: Slow to moderate, gradually developing rounded to cylindrical stems.
Soil: A fast-draining cactus mixture containing pumice, fine gravel, and moderate organic matter.
Watering: Water thoroughly during active growth, allowing the medium to dry between waterings. Keep mostly dry during winter.
Fertilizing: Apply diluted cactus fertilizer every 2–3 weeks during active growth.
Light: Bright light to partial sun. Strong light encourages compact growth and dense white hairs.
Pests and Diseases: Mealybugs, scale insects, spider mites, and root rot.
Germination Info:
Temperature: 27 °C.
Surface Sown: Yes. Press seeds lightly onto the growing medium.
Germination Time: Approximately 7–28 days.
Moisture: Maintain consistent moisture without saturation.
Light: Bright, indirect light.
After Germination: Gradually increase ventilation and introduce brighter light as seedlings establish.
