Sulcorebutia canigueralii
| Light | Bright light with some direct sun; a little shade from the fiercest afternoon sun |
|---|---|
| Water | Regularly through the warm growing season once the mix has dried; keep completely dry in winter |
| Soil | Gritty, fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Tolerates cold when bone dry; protect from hard frost. Roughly USDA zones 9a–11 |
| Propagation | Seed, and division of offsets from the clump (see Propagation — offsets) |
| Toxicity | Non-toxic to cats and dogs |
Sulcorebutia canigueralii is a small, clustering globular cactus from the highlands of south-central Bolivia, prized by collectors for its vivid bicoloured flowers with red to magenta outer petals and a contrasting yellow to orange centre. Like other members of the genus Sulcorebutia, it is a compact, free-flowering plant that stays small enough for a windowsill yet rewards its grower with an outsized spring display.
Description
Sulcorebutia canigueralii forms small, flattened-globular stems only a few centimetres across, usually clustering with age into low cushions of many heads. The body is typically dark green to purplish, ribbed and broken into low tubercles in the manner characteristic of the genus. Each areole carries short, fine, comb-like (pectinate) spines that press closely against the body — often pale and bristly rather than fierce.
The flowers are the plant's chief glory. Borne low around the base of the stems in spring, they are funnel-shaped and open wide in sun, showing red to carmine-magenta outer petals around a yellow to orange throat. This crisp two-tone effect is what sets the species apart from its many single-coloured relatives, and it has made S. canigueralii a favourite parent in collections. The plant has a thick, somewhat swollen rootstock, a common feature in Sulcorebutia that helps it survive dry, cold dormancy.
Distribution and habitat
The species is native to Bolivia, in the mountainous country of the Chuquisaca region near Sucre. It grows at high elevation among rocks and in gritty, well-drained ground, where nights are cold and the growing season is defined by a distinct wet summer and a dry winter. These montane conditions explain its cultivation needs: strong light, sharp drainage, and a completely dry, cool rest.
Cultivation
Sulcorebutia canigueralii is one of the more rewarding small cacti to grow, provided its roots are never left wet and cold. Plant it in a very free-draining, mostly mineral mix and give it bright light with a little shade only from the most intense afternoon sun; ample light keeps the plant compact and encourages heavy flowering. Water freely during the warm months once the mix has dried out, then withhold water entirely as the days shorten. See Watering and Repotting for general technique.
A cold, bone-dry winter rest is the single most important factor in getting a good spring display — plants kept warm and moist through winter flower poorly and are far more prone to rot. When dry, the fleshy roots tolerate surprising cold, but they resent standing wet, so err always on the side of underwatering.
Propagation
The species is easily raised from seed, which germinates readily on a warm, gritty surface, and seedlings reach flowering size within a few years. Because it clusters freely, established plants can also be divided: detach a rooted or unrooted offset, let any cut surface callus, and pot it into the same mineral mix. See Propagation — offsets for the method. As with the whole genus, seed-raised plants preserve the most natural variation, while division reliably reproduces a chosen individual.
Common problems
- Rot — the usual cause of loss, almost always from wet, cold roots or a slow-draining mix; the stems soften and discolour from the base.
- Poor flowering — generally a sign of too little light or too warm and moist a winter; give a cold, dry rest to fix it.
- Etiolation — insufficient light causes the normally squat stems to stretch and pale, spoiling the tight cushion form.
- Pests — root mealybugs hiding among the roots, along with red spider mites and ordinary mealybugs on the body, are the pests to watch for (see Pests and diseases).
See also
- Sulcorebutia — the genus overview
- Soil and potting mix · Watering · Propagation — seed · Propagation — offsets · Repotting