Gibbaeum heathii
| Light | Bright light; full sun to light shade, colours best with strong light |
|---|---|
| Water | Very sparingly; water in the cooler growing months, keep nearly dry in the heat of summer |
| Soil | Gritty, fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; roughly USDA zones 9b–11 |
| Propagation | Seed or division of clumps |
| Toxicity | Not known to be toxic to cats or dogs |
Gibbaeum heathii is a small, clump-forming mesemb from the Little Karoo of the Western Cape, South Africa. Each plant body is a smooth, pale grey-green to bluish, near-spherical pair of fused leaves split by a shallow fissure, from which emerge showy white to pink daisy-like flowers. It belongs to the genus Gibbaeum, a group of dwarf succulents in the ice-plant family Aizoaceae prized by collectors for their plump, almost pebble-like forms.
Description
Gibbaeum heathii consists of one to several leaf-pairs, each pair fused into a firm, egg- to globe-shaped body a few centimetres across, cleft along the top by a narrow fissure. The surface is smooth and slightly waxy, coloured pale grey-green to bluish and often flushed with subtler tones in strong light, which gives the plant its characteristic stone-like look. With age the plants offset and build up into low, tidy clumps.
Flowers appear from the fissure, typically in the cooler part of the year. They are relatively large for the size of the body, white to soft pink, and open by day in the manner of most members of the Aizoaceae. As with many mesembs, the plant renews itself by producing a fresh leaf-pair that draws on the old one, so the previous body gradually shrivels as the new growth swells.
Distribution and habitat
The species is native to the Little Karoo (Klein Karoo) region of the Western Cape in South Africa, a semi-arid winter-rainfall area of low shrubland and quartz flats. There the plants grow low among stones and sparse vegetation, their pale bodies blending into the gravelly ground — a camouflage shared by many dwarf succulents of the region. Rainfall is modest and concentrated in the cooler months, with hot, dry summers.
Cultivation
Gibbaeum heathii is a rewarding but water-sensitive little plant, and overwatering — especially while it is resting — is the usual cause of loss. Grow it in a very free-draining, mostly mineral mix in a shallow pot, in bright light with good airflow. Water carefully during the cooler growing season when the plant is plumping up and in flower, allowing the mix to dry between waterings, and keep it nearly dry through the heat of summer when growth slows. Because its seasonal rhythm is tied to a winter-rainfall climate, watch the plant rather than the calendar and let its appearance guide you: a swelling new leaf-pair signals active growth, while a firm, resting body wants to be left alone. See Watering and Repotting for general technique.
Propagation
The species is easily raised from seed sown on a gritty, mineral surface kept lightly humid and warm; see Propagation — seed. Established clumps can also be divided, and rooted-up offsets treated much like offsets of other clumping succulents — let any cut or torn surface dry before setting the piece on barely-moist mix to root.
Common problems
- Rot — almost always from watering while the plant is resting, or from a slow-draining mix; the body goes soft and translucent.
- Etiolation — too little light makes the bodies bloat, pale and lose their compact, pebble-like form.
- Pests — mealybugs (white fluff in the fissure and around the roots) and the occasional spider mite are the usual culprits; inspect the crevices where the leaf-pairs meet.
See also
- Gibbaeum — the genus overview
- Soil and potting mix · Watering · Propagation — seed · Propagation — offsets · Repotting · Pests and diseases