These plants are fresh imports and have minimal roots, but are all healthy.
Colouration
Please note that each plant has unique colouration and shape, as they are seed grown. The plant that you receive may be somewhat different from the photos.
Origin and Natural Habitat
Gymnocalycium mihanovichii is indigenous to Paraguay and Argentina, though the variegated form is generally only seen in cultivation.
Plant Characteristics
Gymnocalycium mihanovichii, also known as the “Chin cactus”, has soft, brittle spines protruding from chin-like ridges. These particular specimens have striking colorful variegation covering most of their stem surface.
Care Guide
Light
Gymnocalycium can tolerate full morning sun if carefully adjusted to it, but a plant grown in some shade or a newly replanted specimen should not be placed in full sun immediately. It is best to grow them under 40%-60% shade cloth.
Soil
Gymnocalycium mihanovichii is a relatively easy to grow cactus, but should only be planted in a gritty, inorganic soil medium that drains well, such as Ibaraki Akadama or Hyuga pumice.
Water
You should thoroughly soak the soil when watering. Only water this species in the spring and summer growing season, and keep dry in autumn and winter. Gymnocalycium are extremely prone to rot if watered in winter.
Pot size
Gymnocalycium are small cacti, even when mature. This species tends produce offsets when it gets older. Small plants can be grown in 10cm pots until they start to grow near the edges of the pot, at which point they can be moved to larger pots. They should only be planted in a pot that is 3-5cm wider than their stem diameter.
Temperature
This species’ ideal temperature ranges between 25 – 35°C. It can tolerate 5 – 35°C. It is very sensitive to frost.
Humidity
Gymnocalycium mihanovichii are sensitive to humidity, particularly during winter. This species tends to rot in high humidity. Make sure that your growing space has plenty of airflow.
Fertilizing
Use a half-strength diluted general liquid fertilizer only during the growing season. Do not fertilize during autumn or winter. Alternatively, a small amount of slow-release fertilizer will be sufficient.
Growing Season
Gymnocalycium mihanovichii grow actively in spring and summer, and are fully dormant in autumn and winter.
In South Africa, their growing season is from October until late February.
Propagation
Gymnocalycium mihanovichii are best propagated from seed.
Seed germination: Seeds should be sown in early spring. Plant them in a well-drained coco peat based mix in an airtight container. Once most of the seeds have germinated, remove the lid of the container to allow airflow. Gently mist the seedlings every few days so that the soil does not dry out completely. Plant out after 1 year.