Moon cactus care guide
Gymnocalycium mihanovichii
Quick answer
Water your moon cactus when the top 5 cm (2 in) of soil feel dry. In summer that’s typically every 11 to 17 days.
- WateringEvery 11 to 17 days · summer
Every 28 to 42 days, sometimes less often · winter - LightBright / direct light
- Climate18–27 °C (64–81 °F)
- Pet safetyNot confirmed pet-safe
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5 cm (2 in)
- Summer · Jun–AugEvery 11 to 17 days
- Winter · Dec–FebEvery 28 to 42 days, sometimes less often
Use room-temperature water and let any excess drain. Never leave the pot sitting in standing water.
Work out your own rhythm with the watering calculator.
Light and placement
Bright / direct light
Moon cactus needs several hours of direct sun. Turn the pot every week so it grows evenly. Place it directly in front of a south- or southwest-facing window.
Feeding
Feed your moon cactus every 30 days while it’s actively growing. Use a cactus and succulent fertilizer, which is lower in nitrogen, at half the strength on the label, and only on soil that’s already damp.
When growth pauses, skip the fertilizer and let it rest.
Temperature & humidity
Climate18–27 °C (64–81 °F)
Humidity30–60%
During leafy growth, aim for 18–27 °C (64–81 °F). For routine indoor care, keep it above about 10 °C (50 °F) and avoid cold drafts. This is a care guideline, not an exact damage threshold. Cooler overwintering depends on the species and its rest conditions.
It does best at 30–60% humidity. It doesn’t need misting.
Not confirmed pet-safe
Common questions
How often should I water a moon cactus?
Water your moon cactus (Gymnocalycium mihanovichii) when the top 5 cm (2 in) of soil feel dry. In summer, that’s typically every 11 to 17 days. In winter, slow down to every 28 to 42 days, sometimes less often.
How much light does a moon cactus need?
Moon cactus needs several hours of direct sun. Turn the pot every week so it grows evenly. Place it directly in front of a south- or southwest-facing window.
Sources
- This guide follows established plant-care guidance and official ASPCA pet-safety references. How we verify our plant data →
- How we check our plant advice
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