Demanding Cactus Safe for pets

Sand Dollar Cactus

Astrophytum asterias

A small, spineless, flattened globular cactus resembling a sand dollar, covered in tiny white flecks.

The essentials at a glance

Watering

Every 10 days
Light

Full sun
Humidity

10–30 %
Temperature

10–30 °C

How to care for your Sand Dollar Cactus

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

The Sand Dollar Cactus is a highly sought-after, distinctive, spineless cactus. Its flattened, disc-like shape, often with eight subtle ribs, and covering of small white flecks give it the appearance of a sand dollar. It produces beautiful yellow, often red-throated, flowers from its fuzzy apex in summer. This cactus requires careful cultivation, demanding bright indirect to full sun, excellent drainage in a very gritty mix, and extremely careful watering to prevent rot, especially in winter.

Watering your Sand Dollar Cactus

Every 10 days

Water thoroughly from the bottom or top; let dry completely.

How to know it needs water

Soil completely dry
Body feels slightly less firm

How much light a Sand Dollar Cactus needs

Full sun

Bright indirect to full sun

Direct sun tolerated: 5 to 10 h a day
Orientations that suit it: South, South-east, South-west, East, West

Humidity and misting

10–30 %

Low Not needed. Prefers dry air.

Feeding and fertiliser

Every 45 days

Sparingly, 2-3 times during spring/summer. Over-fertilizing can harm.

Recommended feed: Weak, low-nitrogen cactus fertilizer · 2-7-7

Repotting your Sand Dollar Cactus

Every 24 months

Use a very gritty, mineral-rich, well-draining cactus mix. Handle roots gently.

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

The tell-tale signs

Root-bound
Stunted growth
Soil depletion

Pruning your Sand Dollar Cactus

Not applicable. N/A

Through the year

Watering is not set once and for all: it follows the light and the growth. Allow 25 days between waterings in the depth of winter, against 8 in the growing season.

25 J
25 F
15 M
8 A
8 M
8 J
8 J
8 A
10 S
15 O
25 N
25 D

Active growth · Days between waterings

Good to know

Known for its perfectly symmetrical, flattened, disc-like shape
Also called 'Sea Urchin Cactus' or 'Starfish Cactus'
Highly prized by collectors for its unique form and lack of spines.

Frequently asked questions about the Sand Dollar Cactus

How do you care for a Sand Dollar Cactus?

Water it every 10 days. Give it full sun. Ideal humidity: 10–30 %. Ideal temperature: 10–30 °C. Water thoroughly from the bottom or top; let dry completely.

How often should you water a Sand Dollar Cactus?

Every 10 days Water thoroughly from the bottom or top; let dry completely. How to know it needs water : Soil completely dry ; Body feels slightly less firm.

How much light does a Sand Dollar Cactus need?

Full sun Bright indirect to full sun 5 to 10 h a day

Is the Sand Dollar Cactus toxic to cats and dogs?

No, the Sand Dollar 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 Sand Dollar 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 Sand Dollar Cactus?

Repot every 24 months, ideally in spring. Use a very gritty, mineral-rich, well-draining cactus mix. Handle roots gently.