Astrophytum Ornatum “Star Cactus” Care & Buying Guide


Light requirements High
Water requirements Low
Ease of care Easy
Size Medium
Toxicity Non-toxic
Zone 10a
Temperature resistance Not frost-hardy
Growth speed Medium
Indoor growing Suitable


Taking Care Of Astrophytum Ornatum “Star Cactus”

Ideal conditions

Astrophytum Ornatum “Star Cactus” has typical succulent needs – it doesn’t tolerate frost, likes partial to full sun, and requires little water. This star-shaped cactus is thus best to keep outdoors where sunlight is readily available, though it may also be kept indoors.


Water your Star Cactus when its soil is dry to the touch and avoid overwatering it. Overwatering can lead to waterlogging and root rot.

In winter, the Star Cactus will become dormant and will thus require much less water than in winter. This cactus should do well without any water in winter, but you may also very light water it once or twice per month.

Where to plant

Just like pretty much any succulent, Astrophytum Ornatum “Star Cactus” should be planted in porous, fast-draining soil. Such soil would let water through easier and would prevent waterlogging.

For more drainage, you may add mineral grit like perlite, coarse sand, or pumice to the potting mix. No matter what combination of mineral grit you add, make sure that it’s in at least a 1:1 ratio with the mix.

To keep this plant more mobile, plant it in a pot even if you are intending to keep it outdoors. In winter, a potted cactus will be much easier to bring indoors.

As mentioned above, Astrophytum Ornatum “Star Cactus” requires partial to full sunlight, which makes it the best for outdoor growing. With that said, you may grow the Star Cactus indoors as well if you have a spot near a window that receives direct sunlight all day.

No matter where the pot with your Star Cactus is, on very hot days or during heatwaves, temporarily move the cactus to a shaded location. This will prevent sunburn.

General care information

Fertilize your Astrophytum Ornatum “Star Cactus” a few times throughout its growing season (spring & summer). Once every 4-8 weeks should be good enough, depending on your fertilizer. Use a cactus fertilizer mix diluted to around half strength.

The Star Cactus is a fairly slow grower, and fertilizing it should allow you to achieve more consistent and quicker growth.

Although the Star Cactus grows slowly, it can get up to 1 foot tall and 6 inches wide, meaning that you’ll need to repot your cactus a few times in its lifetime. You may repot your Star Cactus only when it seems to have outgrown its pot, but repotting every spring or summer may be more optimal.

More frequent repotting allows you to have a look at the cactus’ roots and remove any damaged or rotten parts. Besides, introduction to fresh soil may boost the growth of Astrophytum Ornatum “Star Cactus”.

Before repotting, allow the cactus soil to dry so that removal is easy. Once the cactus is out, check its roots and remove any damaged parts. And after the plant is repotted, don’t water it for about a week to allow it to recover from stress.


Tammy Slater

Tammy Slater is the founder of, a home and garden blog that provides inspiration and resources for homeowners and renters alike. A self-taught DIYer, Tammy loves nothing more than tackling a new project in her own home. When she's not blogging or spending time with her family, you can usually find her rooting around in the garden or at the hardware store.

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