1How it thrives
Waterlow
Lightbright indirect
Humiditylow
Min. temperature8 °CJanuary
Don’t water – dry winter rest. Slight shrivelling is normal.
No feeding now.
Cool and bright, 8–15 °C: unheated room, stairwell, cold windowsill or frost-free greenhouse.
February
Don’t water – dry winter rest. Slight shrivelling is normal.
No feeding now.
Cool and bright, 8–15 °C: unheated room, stairwell, cold windowsill or frost-free greenhouse.
March
Gentle start: the first small drink once you see buds or new growth and it warms up.
First weak dose at the end of the month if it is actively growing.
Bright spot, east or west window.
Move it somewhere brighter and warmer and end wintering. Get it used to strong sun gradually.
If roots fill the pot: fresh soil, a pot 1–2 cm larger. Water sparingly for a week afterwards.
April
Deeply, but only once the soil is completely dry.
Cactus fertiliser once a month at half strength.
Bright spot, east or west window.
If roots fill the pot: fresh soil, a pot 1–2 cm larger. Water sparingly for a week afterwards.
It flowers next month – once you see buds, don’t move it any more.
May
Deeply, but only once the soil is completely dry.
Cactus fertiliser once a month at half strength.
Semi-shaded balcony or east/west window – protect from harsh midday sun.
After mid-May (last frosts) it can go outside – keep it in partial shade for the first 1–2 weeks to avoid sunburn.
It usually flowers now – don’t turn or move it, and log the bloom in your diary!
June
Deeply, but only once the soil is completely dry – more often in heatwaves, preferably in the evening.
Cactus fertiliser once a month at half strength.
Semi-shaded balcony or east/west window – protect from harsh midday sun.
It usually flowers now – don’t turn or move it, and log the bloom in your diary!
July
Deeply, but only once the soil is completely dry – more often in heatwaves, preferably in the evening.
Cactus fertiliser once a month at half strength.
Semi-shaded balcony or east/west window – protect from harsh midday sun.
It usually flowers now – don’t turn or move it, and log the bloom in your diary!
August
Deeply, but only once the soil is completely dry – more often in heatwaves, preferably in the evening.
Cactus fertiliser once a month at half strength.
Semi-shaded balcony or east/west window – protect from harsh midday sun.
It usually flowers now – don’t turn or move it, and log the bloom in your diary!
September
Deeply, but only once the soil is completely dry.
No feeding now.
Semi-shaded balcony or east/west window – protect from harsh midday sun.
Bring it in when nights drop below 13 °C. Check for pests first.
October
Taper off gradually: very little by the end of the month.
No feeding now.
Bright spot, east or west window.
Move it to its cool, bright winter spot and taper off watering. Log it with one click in the Care hub.
November · now
Don’t water – dry winter rest. Slight shrivelling is normal.
No feeding now.
Cool and bright, 8–15 °C: unheated room, stairwell, cold windowsill or frost-free greenhouse.
December
Don’t water – dry winter rest. Slight shrivelling is normal.
No feeding now.
Cool and bright, 8–15 °C: unheated room, stairwell, cold windowsill or frost-free greenhouse.
Unlike most cacti it dislikes harsh midday sun – bright filtered light is ideal.
Moon cactus – what to know
Moon cactus (Gymnocalycium mihanovichii) belongs to the Cactaceae family (genus Gymnocalycium) and is listed in our catalog under “Cactus”. Its needs – light: bright indirect; water: low; humidity: low. Keep it above 8 °C – it is frost-tender and needs a frost-free spot in winter. Rest period: dry winter rest. Typical flowering time: May, June, July, August. Easy enough for beginners. It is not known to be toxic to cats or dogs. On Perfect Plants Club, one member grows it (1 specimen(s), 1 photo(s)).
All Gymnocalycium species in the catalog →Detailed toxicity data →
Frequently asked questions
How often should I water Moon cactus?
Sparingly: let the soil dry out completely between waterings, and water even less in winter.
How much light does Moon cactus need?
It likes bright but indirect light, such as near an east- or west-facing window.
How cold can Moon cactus get?
Keep it above 8 °C – it is frost-tender and needs a frost-free spot in winter.
Is Moon cactus toxic to cats and dogs?
It is not known to be toxic to cats or dogs.
When does Moon cactus flower?
Typical flowering time: May, June, July, August.
What members’ data shows
When does it really bloom?
No blooms logged yet. If yours flowers, your data will be the first!
Average watering interval
Not enough watering logs yet. Waterings logged in the care hub feed this chart.
Who grows it?
Gallery
Tips and questions about this species
Gymnocalycium
Care data is for guidance only.
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