What Is An Old Lady Cactus – How To Grow An Old Lady Cactus Flower

Old Lady Cactus On Red Rocks
old lady cactus
(Image credit: Tamonwan Amornpornhaemahiran)

The mammillaria old lady cactus has no features similar to an elderly woman, but sometimes there is no accounting for names. This is a diminutive cactus with white spines running up and down, so perhaps that is where the resemblance occurs. This native of Mexico likes well-draining soil and warm temperatures and can be grown outdoors in hot climates or indoors as a houseplant. 

What is an Old Lady Cactus?

Mammillaria is a large genus of cacti that are mostly native to Central America. Old lady cactus care is super easy, which makes it a perfect plant for a beginner succulent owner. With good care and the right situation, the plant may even surprise you with its classic hot pink, old lady cactus flower. 

Mammillaria hahniana is a rounded, chubby, little cactus with up to 30 short, white spines per areole. The entire effect is of a small barrel cactus covered in snowy fur. These cacti grow 4 inches (10 cm.) tall and 8 inches (20 cm.) wide. 

Over time mature cacti form little offsets, which can be divided away from the parent plant and used to start new plants. In late winter to early spring, it will develop funnel-shaped, hot pink flowers with bright yellow anthers that last quite a while. The flowers may form a ring around the top of the plant. Rarely, small orange fruits will follow. 

Growing Mammillaria Old Lady Cactus

You can plant outdoors in USDA zones 11 to 13 or use them in a container and move inside for fall and winter. Either way, the cactus requires well-draining soil that is on the gritty side. 

Place the plant in full sun to partial shade and plant outdoors where there is some protection from the western sun, which can cause sunscald. These cacti need four to six hours of bright light to thrive. 

In order to promote the old lady cactus flower, provide a slightly cooler area in winter. During this time, suspend watering and let soil dry completely. 

Old Lady Cactus Care

The downy little cacti really thrive on neglect. Provide water in the driest periods and gradually reduce in fall. 

You don't necessarily have to feed these plants but in pot bound specimens, a spring feed of diluted cactus food is appreciated. Repot container plants every couple of years with a good cactus mix or make your own with one part topsoil, one part fine gravel or sand, and one part perlite or pumice. 

When repotting, allow the soil to dry out to easily remove the plant, and don't water the new soil for several days to allow the plant to acclimate.

Bonnie L. Grant

Bonnie Grant is a professional landscaper with a Certification in Urban Gardening. She has been gardening and writing for 15 years. A former professional chef, she has a passion for edible landscaping.