Gymnocalycium mihanovichii cv. ‘Black Widow’

The Gymnocalycium ‘Black Widow’ is an extraordinary and rare cultivar of Gymnocalycium mihanovichii, admired for its deep, dark, almost black-purple body that shines with an elegant metallic luster. The cactus forms a compact, globular shape with distinct ribs and small, symmetrical spines — making it look both mystical and exotic.

Unlike most green Gymnocalyciums, the ‘Black Widow’ stands out due to its unique pigmentation, giving it a nearly jet-black or dark maroon tone under bright sunlight. It is a collector’s favorite for its intense coloration, symmetry, and slow-growing habit.

Often grafted onto Hylocereus or Trichocereus rootstock, it can also survive on its own roots if grown with care and in ideal conditions.

🌞 Light Requirements:

• Prefers bright, indirect sunlight.

• Avoid harsh midday sun — strong light enhances the dark coloration but can burn the surface.

• Perfect for balconies, windowsills, or shaded greenhouse setups.

💧 Watering:

• Water moderately during active growth (spring to autumn).

• Let the soil dry completely between waterings.

• In winter, water sparingly or not at all, depending on temperature.

• Always ensure excellent drainage to avoid rot.

🌡️ Temperature & Climate:

• Ideal range: 20°C – 35°C (68°F – 95°F)

• Not frost-tolerant – keep above 10°C (50°F).

• Protect from excessive humidity and cold drafts.

🌱 Soil:

• Use a well-draining cactus mix with 50–60% grit, perlite, or pumice.

• Avoid clay-heavy or moisture-retaining soil.

🌼 Flowering:

• Produces beautiful pinkish-white or pale red blooms from the crown during warm months.

• Flowers contrast dramatically with the dark cactus body, making it visually stunning.

🌸 Fertilizer:

• Use a balanced cactus fertilizer (low in nitrogen) once a month during spring and summer.

• Do not fertilize in winter.

🌿 Propagation:

• Propagated mainly by offsets or grafting.

• Can also be grown from seed under controlled conditions.

💎 Special Features:

• Rare black-colored Gymnocalycium cultivar

• Highly decorative and collectible

• Compact and easy to grow

• Perfect for indoor succulent collections

🏡 Uses:

• Ideal for indoor plant displays, succulent arrangements, and collector collections.

• Excellent gift plant for cactus enthusiasts.

• Great choice for modern minimalist décor due to its bold, dark appearance.