Mammillaria zeilmanniana
| Light | Bright light with some protection from the harshest afternoon sun |
|---|---|
| Water | Regularly in growth once the soil dries; keep dry and cool in winter |
| Soil | Fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; USDA zones 9b–11 |
| Propagation | Offsets (easy); also seed |
| Toxicity | Non-toxic to cats and dogs |
Mammillaria zeilmanniana is a small, freely clustering cactus from central Mexico, best known in cultivation as the Rose Pincushion. It earns the name by reliably encircling itself with a neat ring of violet-pink flowers, often while the plant is still young and only a few centimetres across, which makes it one of the most rewarding and popular beginners' Mammillaria.
Description
Mammillaria zeilmanniana forms a soft, globular to shortly cylindrical body, typically 4–6 cm across, that offsets readily to build up crowded clumps over time. The surface is covered in small, spirally arranged tubercles, each tipped with an areole bearing numerous fine white radial spines and about four stouter, reddish central spines, of which the lowermost is hooked into a little fish-hook — a characteristic of this group of Mammillaria.
The flowers are the plant's great attraction: a full circlet of funnel-shaped blooms, usually a bright violet-pink (a white-flowered form also exists in cultivation), opening around the top of the plant in spring and often repeating through the growing season. The blooms are large and showy for so small a cactus, and appear far more freely than in most of its relatives.
Distribution and habitat
The species is endemic to a very small area of central Mexico, in the state of Guanajuato, near San Miguel de Allende. Its wild range is tiny and it is assessed as critically endangered in habitat, threatened above all by illegal collection for the trade; but the plant is so easy and quick to raise that it is one of the most abundant of all nursery cacti, and virtually every plant in cultivation is nursery-propagated rather than wild-collected.
Cultivation
The Rose Pincushion is an excellent, forgiving beginner's cactus, and flowers more readily than almost any other small cactus. Grow it in a free-draining, mostly mineral mix in bright light, with a little shade from the fiercest summer sun to keep the body from scorching. Water regularly through the growing season once the soil has dried, then withhold water and keep the plant cool and dry through winter — this winter rest both prevents rot and encourages the spring flush of flowers.
Like most clustering Mammillaria, it appreciates being potted on as clumps fill their container. See Watering and Repotting for general technique.
Propagation
The easiest method is by offsets: individual heads or small clusters can be gently detached, left to callus for a few days, and set on a barely-moist mineral mix to root. The species also comes readily from seed and flowers young, so seed-raised plants reach blooming size quickly. See those guides for full walkthroughs.
Common problems
- Rot — the most common cause of loss; usually from overwatering, a slow-draining mix, or water left sitting in the crown. The plant softens and browns from the base.
- Etiolation — too little light makes the body stretch and pale, and the plant flowers poorly.
- Pests — mealybugs (white fluff among the tubercles and roots) and red spider mites (fine webbing, bronzed skin) are the usual offenders. See Pests and diseases.
See also
- Mammillaria — the genus overview
- Soil and potting mix · Watering · Repotting · Propagation — offsets · Propagation — seed · Pests and diseases