Haworthia mirabilis
| Light | Bright, filtered light; some direct sun to bring out colour, but shade from harsh midday sun |
|---|---|
| Water | Moderate in the growing seasons (autumn and spring); keep dry through the hot midsummer and cold midwinter rests |
| Soil | Gritty, fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; USDA zones 9b–11 |
| Propagation | Offsets, leaf cuttings and seed |
| Toxicity | Non-toxic to cats and dogs |
Haworthia mirabilis is a small, low-growing rosette succulent from the winter-rainfall regions of the Western Cape of South Africa, and one of the most variable of the "retuse" Haworthia species. Its fleshy leaves curve back on themselves to present flat or gently rounded windowed faces, finely patterned with translucent veins; grown in good light the whole plant can flush a warm red-purple, making it a favourite among collectors of windowed haworthias.
Description
Haworthia mirabilis forms compact rosettes of thick, triangular leaves, usually only a few centimetres across, that may stay solitary or slowly offset into small clusters. The upper part of each leaf is recurved — the tip bends back toward the soil — so that the plant presents a flattened top made up of the leaf faces. These faces, or "windows", are semi-transparent and traced with a network of fine pale veins, an adaptation that lets light down into the leaf while the body sits low and partly buried in habitat.
The species is famously variable: leaf colour ranges from soft green to deep reddish-bronze depending on light and season, the leaf margins and keels often carry small translucent teeth or bristles, and the amount of window and veining differs greatly from population to population. In strong light the leaves take on the red-purple flush that gives the plant much of its appeal. Slender flower spikes rise well above the rosette in season, carrying small, tubular white flowers marked with brownish or greenish stripes.
Distribution and habitat
The species is native to the southern Western Cape of South Africa, in the winter-rainfall belt around the Overberg and neighbouring districts. It grows in a wide range of situations — among quartz gravel, in rocky clefts and on shale or sandstone slopes — often tucked between stones or partly withdrawn into the soil, with only the flat leaf windows exposed to the sky. Because so many local forms have been described, H. mirabilis is best thought of as a broad, geographically variable species rather than a single uniform plant.
Like all haworthias, it is protected in the wild and should only be bought as nursery-propagated stock; wild collection is both damaging and, in South Africa, illegal.
Cultivation
Haworthia mirabilis is an undemanding houseplant if its cool-season growing rhythm is respected. Grow it in a gritty, mostly mineral mix in a pot that drains freely, and give it bright light: enough sun to keep the rosette compact and to draw out the red-purple colouring, but with shade from the fiercest midday sun, which can scorch the windowed faces.
This is a cool-season grower, most active in the milder, brighter months of autumn and spring. Water thoroughly when the mix has dried, chiefly during these growing seasons, and ease right off during the heat of midsummer and the cold of deep winter, when the plant naturally rests. As with most windowed haworthias, overwatering — especially in a heavy mix or a stagnant, hot period — is the main cause of loss. See Repotting for general technique; the plant is happy to stay potbound and flowers more reliably when snug.
Propagation
H. mirabilis can be increased in several ways. Clustering plants can be divided, lifting rooted offsets away from the parent. Individual leaves pulled cleanly from the base and left to callus may root and pup, though retuse haworthias strike from leaf far less reliably than freely clumping kinds (see Propagation — cuttings). Seed is used where the natural variability is prized, since seedlings show the full range of forms — though haworthia seed needs cross-pollination between two genetically distinct plants to set.
Common problems
- Rot — from overwatering, a slow-draining mix, or watering during the hot summer rest; the rosette softens and browns from the base.
- Etiolation — too little light makes the rosette stretch and pale, opening up and losing both its tight form and its red colouring.
- Scorch — sudden strong midday sun on unacclimatised plants can bleach or mark the leaf windows.
- Pests — mealybugs (white fluff between the leaves and at the roots) and the occasional fungus gnat in soggy mixes are the usual culprits. See Pests and diseases.
See also
- Haworthia — the genus overview
- Soil and potting mix · Watering · Repotting
- Propagation — offsets · Propagation — cuttings · Propagation — seed