Moon Cactus (Gymnocalycium mihanovichii)

Moon Cactus

Gymnocalycium mihanovichii

Its bright grafted top is a tiny desert jewel, popping with vivid color. Succulent cactus; common name: Moon Cactus.

Partial sun
0.5/week
Beginner
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Plant Needs

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Sunlight Bright indirect to partial direct sunlight; avoid intense midday summer sun to prevent scion sunburn
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Watering Allow soil to fully dry between waterings; avoid overwatering to prevent root rot on the rootstock
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Temperature Thrives at 18–25°C; protect from frost below 10°C to prevent tissue damage
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Characteristics

  • Stem: Grafted scion is spherical, spineless or with tiny, sparse spines; rootstock is typically a Hylocereus species
  • Flower: Pale pink or white funnel-shaped blooms, 3–5 cm wide, emerging from scion crown
  • Fruit: Small, berry-like, green to pink when ripe (rarely produced indoors)
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Care Guide

Watering

Water thoroughly when soil is completely dry; drain excess water immediately

Fertilization

Diluted cactus fertilizer once every 2 months. Cease fertilization in winter during dormancy to prevent root burn

Eggshell powder topdress:Grind dried eggshells to fine powder; sprinkle lightly on soil surface; avoid direct contact with the graft union to prevent irritation
Pruning
  • Remove any yellowing or rotting sections of the rootstock immediately to stop spread of decay
  • Trim overgrown rootstock stems to maintain a compact, balanced form
  • Avoid cutting or disturbing the graft union to preserve the scion’s attachment to the rootstock
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Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: ASPCA: Non-toxic to cats

Humans: No known toxic effects on humans

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Garden Uses & Culture

Culture: Symbolizes resilience and vibrant joy in small, limited growing spaces

Usage: Ornamental indoor succulent; ideal for desk, windowsill, or succulent terrarium decor