Rebutia marsoneri
| Light | Bright light with some direct sun; a little shade from the harshest summer afternoon |
|---|---|
| Water | Regularly in spring and summer once the mix has dried; keep bone dry and cold in winter |
| Soil | Gritty, fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Hardy to near freezing if kept dry; a cold, dry winter rest is essential for flowering |
| Propagation | Seed and offsets |
| Toxicity | Non-toxic to cats and dogs |
Rebutia marsoneri is a small, clustering cactus from the mountains of northwestern Argentina, prized among growers for its unusually clear golden-yellow flowers. Where most Rebutia are known for vivid orange and red blooms, R. marsoneri stands out with pure yellow cups that ring the base of the plant in spring, making it a sought-after but less common member of a very free-flowering genus.
Description
Rebutia marsoneri forms a low, more or less globular body that clusters with age into a cushion of small heads, each only a few centimetres across. The green to slightly bronzed stems are patterned with spiralling ribs broken into small tubercles, and are covered in short, fine, bristly spines — variable in colour from whitish to golden or brownish and often dark-tipped, and thin and flexible enough to give the plant a soft look rather than a fierce one.
The flowers are the main attraction. They open wide and funnel-shaped, in a clear, bright golden-yellow, and emerge in a ring low down around the base of the stems rather than from the top. As with the genus generally, a well-grown, mature plant can almost disappear beneath its blooms for a few days in the flowering season. The species is variable, and some forms run to orange or carry a darker, reddish throat, but the classic and most sought-after plants are unmistakably yellow.
Distribution and habitat
The species is native to the highlands of northwestern Argentina, in the provinces of Jujuy and Salta, where it grows at altitude among rocks on mountain slopes and outcrops. Like most Rebutias, it experiences strong sun, sharp drainage and a cold, dry winter in habitat — conditions worth remembering when growing it, as they explain both its hardiness and its need for a genuine winter rest.
Cultivation
Rebutia marsoneri is an easy and rewarding plant, well suited to beginners. Grow it in a gritty, free-draining mineral mix in a pot that is not too large, in bright light with as much sun as you can give it short of scorching in high summer. Water freely through the growing season once the mix has dried, then reduce sharply in autumn.
The single most important thing for flowering is a cold, dry winter rest: kept dry, the plant tolerates near-freezing temperatures and will reward you with a heavy flush of bloom in spring. Plants that are overwatered or kept warm and growing through winter tend to flower poorly and are far more prone to rot. See Watering and Repotting for general technique.
Propagation
Both seed and offsets work well. Established clumps produce offsets that can be detached and rooted once their cut surfaces have callused, giving quick, flowering-sized plants (see Propagation — offsets). Rebutias also set seed readily and germinate easily on a warm, gritty surface, which is the usual route to larger numbers and to raising new colour forms (see Propagation — seed). Seed-raised plants can flower within just a few years.
Common problems
- Rot — the usual cause of loss, almost always from overwatering, a slow-draining mix, or winter moisture combined with cold.
- Poor flowering — plants kept too warm, too wet, or too shaded through winter often skip their spring display; a cold, dry rest fixes this.
- Pests — mealybugs (white fluff in the crevices and on the roots) and red spider mites are the most common; check the root zone at repotting. See Pests and diseases.
See also
- Rebutia — the genus overview
- Soil and potting mix · Watering · Propagation — seed · Propagation — offsets · Repotting