Moon Cactus
Gymnocalycium mihanovichii (grafted)
The Moon Cactus is not one cactus, but a grafted combination of two: the vibrant, color-mutated Gymnocalycium mihanovichii on top (which can’t produce chlorophyll), and a green cactus base (usually Hylocereus) that keeps it alive. The result is a bright pink, orange, yellow, or red cactus “ball” sitting atop a green stalk — and it’s an instant conversation piece.
This unique cactus thrives in bright, indirect light, and it’s compact enough to live happily on desks, windowsills, or in mixed cactus arrangements. It’s low-maintenance but short-lived compared to most cacti due to the eventual separation of the grafted parts.
Perfect for beginners, gifts, and anyone looking for a splash of color with minimal care needs.
Quick Info
- Light: Bright
- Water: Low
- Size: 4–8 inches tall
- Humidity: Low
- Temp: 65–80°F (18–27°C)
- Flowering: Yes
- Type: Cactus
- Dog Safe: No
- Cat Safe: No
- Kid Safe: Yes
Toxicity Info
- Dog Safe: No
- Cat Safe: No
- Kid Safe: Yes
Notes for Pets: Mildly toxic if ingested
Care Instructions
- Use well-draining cactus/succulent mix
- Water every 2–4 weeks, allowing soil to dry fully between
- Place in a bright, indirect light spot — avoid harsh afternoon sun
- Avoid overwatering; the graft can rot easily
- Repot only if the rootstock outgrows the pot
Common Problems
- Rotting base or top: Overwatering or poor drainage
- Fading color: Not enough light
- Separation: Grafted top may detach over time (normal aging)
FAQs
Because of its bright, round top that looks like a glowing moon — especially in neon pink or yellow.
Not on its own — the colorful top lacks chlorophyll, so it must be re-grafted to another green cactus.
Typically 1–3 years, depending on care and graft health. They’re beautiful but short-lived.
Related Plants
Barrel Cactus
A round, spiny cactus with golden ribs and a striking sculptural look — the Barrel Cactus is a low-maintenance desert beauty perfect for sunny spots.
Fairy Castle Cactus
A charming, castle-like cactus with columnar stems that resemble towers — the Fairy Castle Cactus is a sculptural, slow-growing favorite for windowsills and small spaces.