RUBBY BALL CACTUS – MOON CACTUS

“Moon Cactus” and “Red Cup Cactus”, this plant has a small, spherical shape with distinctive, curved spines and deep red or purple flowers. The colorful red top is a gymnocalycium, which refers to the flower buds bearing no hair or spines.

The ruby ball cactus, also known as Gymnocalycium mihanovichii var. friedrichii or “moon cactus,” is a popular ornamental plant due to its vibrant red, pink, or orange top. Here’s a complete care guide for your ruby ball cactus:

1. Light Requirements

Bright Indirect Light: Place it in a spot with filtered sunlight, as direct sunlight can scorch the colorful top.

Indoors, a south- or east-facing window works well.

If grown outdoors, provide partial shade.

2. Watering

Moderate Watering: Allow the soil to dry out completely between waterings. Overwatering can lead to root rot.

Water once every 2–4 weeks, depending on the season (less in winter).

3. Soil

Well-draining Soil: Use a cactus or succulent mix. You can mix standard potting soil with sand or perlite for better drainage.

4. Temperature and Humidity

Temperature: Thrives in temperatures between 18–26°C (65–80°F). Protect it from frost or extreme cold.

Humidity: Prefers low humidity. Keep it in a dry environment.

5. Fertilizer

Feed during the growing season (spring and summer) with a diluted cactus fertilizer once a month.

Avoid fertilizing in fall and winter when the plant is dormant.

6. Repotting

Repot every 2–3 years to refresh the soil or if the plant outgrows its container.

Be gentle to avoid damaging the delicate roots.

7. Pest and Disease Management

Watch out for mealybugs or spider mites. Use insecticidal soap or neem oil to treat infestations.

Avoid overwatering to prevent fungal diseases.

8. Special Note

The ruby ball cactus is a grafted plant, meaning the colorful top is attached to a green rootstock. If the rootstock dies, you can re-graft the top onto a healthy rootstock.