Turbinicarpus viereckii
| Light | Bright light with a little shade from the hottest afternoon sun |
|---|---|
| Water | Sparingly; let the soil dry completely between waterings, dry rest in winter |
| Soil | Very free-draining, mostly mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; happiest in USDA zones 9b–11, tolerates a cool, dry winter |
| Propagation | Seed (primary); offsets from clustering plants |
| Toxicity | Non-toxic to cats and dogs |
Turbinicarpus viereckii is a small, slow-growing cactus from northeastern Mexico, prized by collectors for its neat globular body, white spines and pink to magenta flowers. Long shuffled between genera, it was for many years placed in Gymnocactus and is still sold under that name, but is now generally treated as a member of the genus Turbinicarpus.
Description
Turbinicarpus viereckii forms a small head a few centimetres across that commonly clusters with age, though plants may also remain solitary. The body is dull green to grey-green and divided into low tubercles arranged in gentle spirals. Each areole carries numerous spreading, rigid white radial spines, often brown- or black-tipped, together with a few longer central spines, giving the plant a distinctly bristly, spiny look.
Flowers appear mainly in spring, opening in a flush of pink to bright magenta blooms that are large in proportion to the little body. As with many members of the genus, the plant has a thickened, swollen root and in habitat pulls itself down into the ground during drought.
Distribution and habitat
The species is native to northeastern Mexico — the state of Tamaulipas and the neighbouring states of Nuevo León and San Luis Potosí — where it grows on calcareous (limestone) rocks and cliffs in dry scrub, often tucked into crevices or wedged among stones. Like most Turbinicarpus, it grows in exposed, gritty sites with sharp drainage and long dry spells punctuated by seasonal rain.
As with the whole cactus family, T. viereckii is listed under CITES (the genus Turbinicarpus is included on Appendix I), and wild collection is neither legal nor necessary — nursery-raised, seed-grown plants are widely available and inexpensive.
Cultivation
Turbinicarpus viereckii is a good introduction to the genus: compact, forgiving of a cool winter, and happy on a sunny windowsill or in a bright greenhouse. Grow it in a very free-draining, mostly mineral mix in a pot deep enough for its thickened roots, and give it bright light with just a little shade from the fiercest summer sun.
Water thoroughly only once the soil has dried right out, then wait; err on the side of underwatering, as the fine roots and swollen rootstock rot easily in cold, wet compost. Keep the plant dry and cool through winter — this rest both prevents rot and encourages the following spring's flowers. See Watering and Repotting for general technique.
Propagation
Seed is the usual and most rewarding method. The fine seed germinates readily on a warm, damp mineral surface, and seedlings, while slow, are not difficult to grow on. Plants that have clustered can also be increased by removing rooted offsets, though the species is grown far more often from seed. See Propagation — seed and Propagation — offsets for details.
Common problems
- Rot — the commonest cause of loss, almost always from watering too often or a mix that stays wet; the plant softens at the base or from the roots.
- Etiolation — too little light stretches the body and spaces out the tubercles, spoiling the neat globular shape.
- Pests — root mealybugs on the roots and red spider mites on the body are the ones to watch for; see Pests and diseases.
See also
- Turbinicarpus — the genus overview
- Gymnocactus — the former genus placement
- Soil and potting mix · Watering · Propagation — seed · Propagation — offsets · Repotting