Light
Bright Indirect Light
Bright indirect light or filtered morning sun is perfect.
Reference image 
Reference image Gymnocalycium neuhuberi
Neuhuber's Chin Cactus
Overview
Gymnocalycium neuhuberi is a highly sought-after, solitary globose cactus in the family Cactaceae. Due to its restricted natural distribution and habitat degradation, this species is considered critically endangered in the wild.
Taxonomy and Naming
The genus name Gymnocalycium originates from the Greek 'gymnos' (naked) and 'kalyx' (bud), referring to the flower buds which lack hair or spines 1. The specific epithet neuhuberi honors the Austrian cactus expert and specialist Gert Neuhuber, who made significant contributions to the genus study 2.
Distribution and Habitat
This species is endemic to San Luis Province in Argentina. It naturally thrives at elevations between 1,000 and 1,500 meters above sea level, primarily growing in rocky, granitic crevices and steep slopes amongst sparse grasses.
Appearance
This cactus features a solitary, flattened-globose stem of pale blue-green to grayish-green coloration. It has distinct ribbed structures decorated with strong, needle-like spines that curve slightly backward. During late spring, it produces beautiful, fragrant, funnel-shaped flowers in shades of lilac, pinkish-violet, or pale purple.
Cultivation
In cultivation, Gymnocalycium neuhuberi is straightforward to grow. It prefers bright, filtered light and requires excellent drainage. Watering should be deep but infrequent, allowing the substrate to dry completely between applications 2.
Common Cultivation Mistakes
The most frequent issue is root rot caused by poorly draining soil or overwatering. Keeping the plant in humid, unventilated indoor spaces can promote fungal attacks. Skipping the cold winter rest will also inhibit blooming.
References
Watering
10-30 Days
Water thoroughly only when the soil is dry. Keep dry in winter.
Soil
Excellently draining, mineral-rich cactus soil with pumice and coarse sand
Requires highly porous, mineral-based cactus mix with pumice.
Safety
Pet Friendly
Non-toxic, but sharp spines require careful handling.
Difficulty
Easy
Easy; very resilient if not overwatered and given winter rest.
Native Habitat
San Luis, Argentina
Endemic to high-altitude rocky slopes and granitic crevices in San Luis Province, Argentina.
Frequently Asked Questions
How large does Gymnocalycium neuhuberi grow?
It usually remains solitary, reaching a compact, flattened-globose shape of about 7-10 cm in diameter.
What color are the flowers and when do they bloom?
It produces fragrant, lilac to light purple, funnel-shaped flowers at the crown in late spring to early summer.
Is it toxic to pets?
No, Gymnocalycium neuhuberi is non-toxic to cats and dogs, though its sharp spines can cause physical injury.
What kind of pot and soil should be used?
Use a pot with drainage holes and highly porous soil rich in pumice, perlite, and coarse sand.
How often should it be watered in winter?
During winter dormancy (November to March), the soil should be kept almost completely dry.
Can it take direct sunlight?
Morning sun or filtered bright light is ideal. Harsh, direct midday sun can cause sunburn on the epidermis.
What is its growth rate?
Like most slow-growing cacti, it has a slow growth rate and requires patience.
How do I encourage it to bloom?
Providing a cool (5-10°C) and completely dry winter rest dormancy is key to stimulating spring flowering.
How do I prevent root rot?
Prevent root rot by watering only when the soil is dry and never letting the pot sit in standing water.
How is it propagated?
It is mainly propagated by seeds, or occasionally by separating basal offsets if any develop.