Easy Cactus Safe for pets

Old Lady Cactus

Mammillaria hahniana

A charming small, spherical cactus densely covered in soft, white, hair-like spines, often producing a crown of pink flowers.

The essentials at a glance

Watering

Every 14 days
Light

Full sun
Humidity

20–40 %
Temperature

18–29 °C

How to care for your Old Lady Cactus

Everything you need to keep your Old Lady Cactus healthy: watering, light, humidity, feeding, repotting and pruning.

Indigenous to Mexico, particularly the states of Guanajuato and Querétaro, *Mammillaria hahniana* is a highly popular and appealing cactus among collectors. It forms a solitary or clumping spherical body, which can grow up to 10 cm (4 inches) in diameter, almost entirely obscured by a dense covering of fine, white, hair-like radial spines and longer, white central spines, giving it a fluffy, aged appearance. In spring, it produces a striking crown of vibrant pink or purplish-red flowers around the apex of its body, forming a beautiful floral wreath. It thrives in bright light and dry conditions, making it an easy-care houseplant.

Watering your Old Lady Cactus

Every 14 days

Water thoroughly until water drains from the bottom. Allow the soil to dry out completely between waterings. Keep almost completely dry during winter dormancy.

How to know it needs water

Soil is completely dry to the touch
Cactus may feel slightly less firm

How much light a Old Lady Cactus needs

Full sun

Bright, direct sunlight for several hours a day. Can tolerate some partial shade, but may flower less.

Direct sun tolerated: 4 to 8 h a day
Orientations that suit it: South, South-east, South-west, East, West

Humidity and misting

20–40 %

Low; requires dry air conditions. Misting is not necessary and can encourage fungal issues on the body of the cactus.

Feeding and fertiliser

Every 30 days

Fertilize during the spring and summer growing season. Avoid fertilizing in fall and winter.

Recommended feed: Diluted liquid cactus fertilizer (low nitrogen, high phosphorus/potassium). · 5-10-10

Repotting your Old Lady Cactus

Every 24 months

Repot into a slightly larger container with fresh, well-draining cactus potting mix. Use gloves or a thick towel to protect hands from spines.

When: Spring
Potting mix: Cactus and succulent mix
Mix in: perlite, pumice, coarse sand

The tell-tale signs

Plant is root-bound
Growth has slowed significantly
Pot is outgrown by the cactus and its offsets

Pruning your Old Lady Cactus

Not typically pruned. Remove any dead or spent flowers by gently twisting them off. Offsets can be removed for propagation.

Through the year

Watering is not set once and for all: it follows the light and the growth. Allow 28 days between waterings in the depth of winter, against 11 in the growing season.

25 J
21 F
14 M
11 A
11 M
11 J
11 J
11 A
14 S
17 O
21 N
28 D

Active growth · Days between waterings

Good to know

Its common name 'Old Lady Cactus' comes from the dense covering of soft, white hairs and spines, resembling an elderly woman's hair.
Like many Mammillaria, it produces a ring of vibrant pink or purple flowers around its apex in spring.

Frequently asked questions about the Old Lady Cactus

How do you care for a Old Lady Cactus?

Water it every 14 days. Give it full sun. Ideal humidity: 20–40 %. Ideal temperature: 18–29 °C. Water thoroughly until water drains from the bottom. Allow the soil to dry out completely between waterings. Keep almost completely dry during winter dormancy.

How often should you water a Old Lady Cactus?

Every 14 days Water thoroughly until water drains from the bottom. Allow the soil to dry out completely between waterings. Keep almost completely dry during winter dormancy. How to know it needs water : Soil is completely dry to the touch ; Cactus may feel slightly less firm.

How much light does a Old Lady Cactus need?

Full sun Bright, direct sunlight for several hours a day. Can tolerate some partial shade, but may flower less. 4 to 8 h a day

Is the Old Lady Cactus toxic to cats and dogs?

No, the Old Lady Cactus is not listed as toxic to cats and dogs. That is still no reason to let your pets chew on it.

Why are my Old Lady Cactus leaves turning yellow?

Yellowing most often comes from too much water: the mix stays wet and the roots suffocate. Check that the pot drains, empty the saucer, and let the mix dry before watering again. Too little light or a cold draught cause the same symptom.

When should you repot a Old Lady Cactus?

Repot every 24 months, ideally in spring. Repot into a slightly larger container with fresh, well-draining cactus potting mix. Use gloves or a thick towel to protect hands from spines.