ARIOCARPUS

Habitat: Texas, New Mexico, Northern Mexico.
Description: they have a short stem with hard, large tubercles and a fleshy taproot. The white, pink or purple flowers arise from the centre. They are adapted to chalky, stony, clayey soils. Some scholars consider Roseocactus and Neogomesia to be subgenera of Ariocarpus.
Soil: 30% clay loam, 20% grit (2-4 mm diameter), pumice stone 30%, 20% chalk; or else 50% mineral soil with no organic matter, 40% sphagnum peat, 10% crushed eggshell; neutral pH. Surround the taproot and the basal region of the stem with fine gravel.
Location: provide plenty of sunshine, dappled light during the hottest months and good air circulation.
Temperature: the minimum temperature can go down to 6 or 8°C (43-46°F) provided the soil is kept dry; however it’s better to keep it a few degrees higher. During the growing period they enjoy some moisture in the air and cool night temperatures.
Water: Be careful not to overwater; apply water thoroughly and let it drain completely. Allow the soil to dry out and wait at least 15 days before watering again in April and May, 7 days in August and September. Watering should be suspended from June to July when the plants enter a semi-dormant state. Provide a good supply of water again in the autumn, then keep the soil dry from the beginning of November to the end of March.
Cultivation tips: not among the easiest in cultivation, it is slow-growing and seldom flowers. Raise from seed or propagate by cutting off a tubercle which must be laid on its flat side on some lightly moist sand. They’re suitable for grafting. It takes 5 to 8 years for these plants to reach maturity, depending on the species. Apply a slow-release fertilizer with microelements in the spring and summer season. The fruits ripen the following spring. They resent root disturbance, so repot the plant only if necessary with January being the best time for this operation. Watch out for root mealy bugs. A narrow, deep clay pot makes an ideal container.
Main species: A. fissuratus, Water once a month from April through to September; it is prone to rot. Mature plants can be overwintered at a minimum temperature of 5°C (41°F).They are naturally found in deserts across Texas and Mexico.
A. retusus, full sun; water from April to July every 2-3 weeks and once a week from August to September.
A. kotschoubeyanus, small plants with triangular tubercles that thrive in chalk; provide water from April to September.
A. trigonus, it has lemon-yellow flowers; recommended minimum temperature:7°C (45°F).
A. scapharostrus, self-fertile, it flowers and fruits profusely. A. agavoides, spines are persistent on mature plants.