Cactaceae
Sand Dollar Cactus (Astrophytum asterias)
Astrophytum asterias
A slow-growing pot cactus for a very bright spot, with direct morning sun and a little shade in the hottest hours. Use an almost fully mineral mix and water only when the pot is completely dry; keep it dry and cool in winter. Too much water is the main cause of loss (rot).
Every 14 days
Bright indirect
-4° - 32°C
30% - 40%
Categories
What is Sand dollar cactus?
Sand dollar cactus (Astrophytum asterias) is a medium-care plant from the Cactaceae family. The sand dollar cactus (Astrophytum asterias) is a small, spineless cactus flattened like a disc: 2.5 to 6 cm tall and 5 to 15 cm across, with 7 to 10 ribs divided by grooves and a line of woolly tufts down the middle of each. The grey-green skin is speckled with tiny white dots. In spring and early...
Sand dollar cactus grows up to 6cm, spread of 15cm, watering every 14 days, -4°C – 32°C, 30–40% humidity. It is suitable for indoor environments and safe for pets.
Unlike many popular species, Sand dollar cactus is safe to keep around pets. Without adequate drainage, root rot can develop within 28 days.
How to Care for Sand dollar cactus?
TLDR: Sand dollar cactus needs Bright indirect, watering every 14 days, and temperatures between -4-32°C with 30-40% humidity.
How Often Should You Water Sand dollar cactus?
In spring and summer, water thoroughly only when the mix is completely dry, usually every 2 weeks. Stop watering when temperatures drop below about 15 °C and keep dry through winter. Cracks in the body mean too much water; a deflated look means it is thirsty.
How Much Light Does Sand dollar cactus Need?
Lots of light: 6 hours of direct sun or an equivalent grow light, with light shade at the peak of summer heat to prevent scorch. Indoors, the brightest window in the house.
What Is the Best Soil for Sand dollar cactus?
Free-draining mix, about 90% mineral (coarse sand, pumice or grit) and 10% organic, with pH 6 to 7. Use a deep pot with a hole, as the plant has a taproot.
What Pot Should You Use for Sand dollar cactus?
A deep, narrow terracotta pot with a drainage hole, only slightly larger than the plant. Repot every 2 years or when snug, in spring, and wait a week before watering.
Care Schedule
Fertilize
Every 30 days
Repot
Every 730 days
What Is Sand dollar cactus and Where Does It Come From?
The sand dollar cactus (Astrophytum asterias) is a small, spineless cactus flattened like a disc: 2.5 to 6 cm tall and 5 to 15 cm across, with 7 to 10 ribs divided by grooves and a line of woolly tufts down the middle of each. The grey-green skin is speckled with tiny white dots. In spring and early summer it opens yellow flowers with a red centre, larger than the plant body, followed by woolly green-to-pink fruit. It is native to a very small area of the lower Rio Grande Valley in Texas and to Tamaulipas in Mexico, where it grows in thorn scrub on rocky ground. In the wild it is threatened: listed as endangered in the US, in CITES Appendix I, and hit by poaching, partly because it is mistaken for peyote. Plants in the trade are seed-grown, and heavily speckled cultivars such as 'Super Kabuto' are popular.
How to Propagate Sand dollar cactus?
Sowing seed
Use seed from cultivated plants. This is the normal way to propagate the species; offsets are rare and grafting is only used to speed up growth.
- 1 Scatter seed on fine, moist mineral mix without covering it.
- 2 Cover the pot with plastic or a clear lid to keep humidity in.
- 3 Keep at 20-25 °C in bright light without strong direct sun.
- 4 Remove the cover gradually once seedlings are established and only prick out at about 1 cm.
Materials needed:
How Big Does Sand dollar cactus Grow?
TLDR: Sand dollar cactus can reach up to 6cm tall with Slow growth rate.
Max height
6cm
Spread
15cm
Growth rate
Slow
Foliage
Evergreen
Plant Uses
Ornamental
Great for decoration
Is your plant showing symptoms?
Click on the symptom to discover possible causes:
What Diseases Commonly Affect Sand dollar cactus?
TLDR: Sand dollar cactus is susceptible to 8 known diseases. Monitor regularly for early detection.
Root Rot
Root rot is a serious fungal disease that affects the root system of plants, causing them to decay and die. It is primarily caused by overwatering, poor drainage, or soil-borne fungi such as Pythium, Phytophthora, Rhizoctonia, and Fusarium. The disease thrives in waterlogged conditions where roots are deprived of oxygen, making them susceptible to fungal infection.
Overwatering
Overwatering occurs when plants receive too much water, depriving roots of oxygen and causing root rot. This environmental stress is one of the most common causes of houseplant death, as waterlogged soil prevents roots from breathing and functioning properly.
Mealybugs
Mealybugs are small, soft-bodied insects covered with a white, waxy, cottony material. They are common pests of houseplants and outdoor plants in mild climates. These sap-sucking insects feed on plant tissue, causing damage, stunted growth, and can lead to plant death if left untreated. They produce sticky honeydew which attracts sooty mold.
Spider Mites
Spider mites are tiny arachnids (less than 1/20 inch long) related to spiders and ticks that feed on plant sap. They thrive in hot, dry conditions and can cause significant damage to ornamental and vegetable plants. During severe infestations, crop losses can reach 14% or higher as these pests disrupt vital plant processes including photosynthesis, carbon dioxide absorption, and transpiration.
Fun Facts
The name asterias comes from Greek and means star-like.
It has been grown as a houseplant since the 1840s.
It is so rare in the wild that it is listed in CITES Appendix I.
Frequently asked questions
How often should I water a sand dollar cactus?
Why is my sand dollar cactus cracking?
Is it cold hardy?
Can I collect one from the wild?
Compare with similar plants
| Attribute | Difficulty | Light | Watering | Pet Safe |
|---|---|---|---|---|
| Dark Fieldcap | Medium | Low light | 2d | ⚠️ |
| Azalea | Medium | Partial shade | 3d | ⚠️ |
| Muriel's Bamboo | Medium | Partial shade | 3d | ✓ |
| Bougainvillea | Medium | Direct sun | 7d | ⚠️ |
