Senecio haworthii
| Light | Full sun to very bright light; needs strong light to keep its dense wool |
|---|---|
| Water | Sparingly; water only when the mix has dried out completely, and ease right off during cold, dark winter months — overwatering is the main killer |
| Soil | Very free-draining, gritty mineral mix (see Soil and potting mix) |
| Temperature | Keep frost-free; USDA zones 9b–11 |
| Propagation | Cuttings (primary); seed |
| Toxicity | Like many former Senecio succulents in the tribe Senecioneae, best treated as toxic if eaten — keep away from pets and children |
Senecio haworthii — under current classification Caputia tomentosa — is a striking white-woolly succulent from the arid interior of South Africa, instantly recognisable for its plump, cylindrical leaves that are wrapped in a dense felt of silvery-white hairs. This coating gives each leaf the look of a little silk cocoon, which has earned the plant its best-known common name, the cocoon plant (also woolly senecio). It belongs to the segregate genus Caputia, into which several woolly, Cape-endemic former Senecio species have been reclassified — distinct from Curio, the genus into which the trailing, succulent-leaved senecios (string-of-pearls and relatives) were moved.
Description
Senecio haworthii is a low, branching subshrub, usually building into a rounded shrublet roughly 20–50 cm tall over time. Its leaves are the whole show: fat, spindle-shaped and cylindrical, tapering at both ends, and completely enveloped in a thick layer of matted white trichomes (hairs). This wool is not merely ornamental — it reflects fierce sunlight and helps the plant conserve moisture in a brutally exposed habitat, and it gives the foliage a soft, chalky, almost snow-white finish.
The stems are also felted when young, becoming woody and bare with age. Mature plants produce small yellow to orange-yellow daisy-like flowerheads, typical of the family Asteraceae, though most growers keep the species chiefly for its remarkable silver foliage rather than its bloom.
Distribution and habitat
The cocoon plant is native to the dry Karoo regions of South Africa — from the southern Richtersveld through the Great and Little Karoo, across the Northern, Western and Eastern Cape — where it grows on exposed, arid, rocky slopes and quartz hillsides under intense sunlight and very low rainfall. In these conditions the dense white felt is a survival adaptation, shielding the water-filled leaves from sunburn and slowing evaporation. Understanding this origin is the key to growing it well: it is a plant of bright light, sharp drainage and long dry spells.
It is a tough, drought-adapted succulent that flowers from summer into autumn in habitat, and this drought tolerance — rather than any strict dormancy — is the rhythm worth respecting in cultivation.
Cultivation
Senecio haworthii is grown for its foliage and rewards a grower who errs on the side of neglect. Give it the brightest position you can — full sun outdoors in suitable climates, or your sunniest windowsill or a spot under strong grow lights indoors. Weak light causes the plant to stretch and, worse, thins out the prized white wool, leaving sparse green patches.
Plant it in a very gritty, fast-draining mix with plenty of mineral content, in a pot that drains freely. This is a species where overwatering is the number-one killer: the felted leaves hide rot until it is well advanced, so water only when the mix is thoroughly dry, and water sparingly. Ease right off during cold, low-light winter months, and protect it from frost. Avoid wetting the woolly foliage where you can, as trapped moisture and dust can mat and spoil the coating. See Watering and Repotting for general technique.
Propagation
The easiest method is stem cuttings. Take a healthy shoot, let the cut end callus over for several days, then set it in a dry, gritty mix and water only lightly until roots form — the same approach used for most succulent cuttings. Take cuttings during the growing season for best results. The species can also be raised from seed, though cuttings are faster and keep the parent's woolly character. See also Propagation — seed.
Common problems
- Rot — by far the most common cause of loss, almost always from overwatering or a slow-draining mix; the felted leaves can mask soft, collapsing tissue until it spreads.
- Loss of wool / etiolation — insufficient light makes stems stretch and the leaves lose their dense white felt, turning greener and sparser.
- Matted, dirty foliage — overhead watering, splashing and dust can spoil the silky coating; keep water off the leaves.
- Pests — mealybugs can hide in the wool and leaf axils, and are easy to overlook against the white felt; inspect regularly (see Pests and diseases).
See also
- Caputia — the genus overview
- Soil and potting mix · Watering · Propagation — cuttings · Propagation — seed · Repotting · Pests and diseases