Senecio (Curio)
Senecio is a huge, worldwide genus in the daisy family (Asteraceae), and among its thousands of species is a distinct group of drought-adapted succulents — trailing, shrubby and columnar plants that store water in fleshy leaves and stems. Many of these succulent species have been reclassified into the genus Curio, though most growers and nurseries still sell and label them under the familiar name Senecio. Grown for their curious bead-, spear- and dolphin-shaped leaves and their easy, low-care nature, they are among the most popular succulents for hanging baskets and windowsills.
Description
Succulent Senecio / Curio species share the daisy-family flower structure but look nothing like a lawn daisy in habit. They store water in swollen leaves that take remarkably varied shapes between species — spherical beads, upswept spears, plump little dolphins, banana-like crescents or flattened blue paddles. Stems may trail and root as they creep, mound into low shrubs, or stand upright in blue-grey columns.
Leaf colour ranges from fresh green through waxy blue-grey, often with a pale, semi-translucent "window" line running down each leaf that lets extra light reach the inner tissue. In good light many species produce small brush-like flowerheads — typically white, cream or pale yellow, and in a few species pleasantly scented of cinnamon. The blooms are modest, and most people grow these plants for the foliage rather than the flowers.
Distribution
The succulent members of the group are concentrated in the drier parts of southern Africa, especially South Africa and Namibia, with additional species scattered elsewhere on the continent. They are plants of arid scrub, rocky slopes and seasonally dry ground, where trailing species drape over rocks and shrubby types root into gritty, fast-draining soils.
Notable species
- Curio rowleyanus (syn. Senecio rowleyanus) — string of pearls, with round bead-like leaves on fine trailing stems; the best known of the group.
- Curio radicans (syn. Senecio radicans) — string of bananas, with glossy crescent-shaped leaves and vigorous trailing growth.
- Curio herreanus (syn. Senecio herreanus) — string of tears / string of watermelons, with pointed, striped beads.
- Curio articulatus (syn. Senecio articulatus) — candle plant, with jointed, sausage-like blue-grey stems.
- Senecio haworthii — cocoon plant, densely covered in white felted wool over cylindrical leaves.
- Curio ficoides (syn. Senecio ficoides) — blue chalksticks, a shrubby species with upswept blue spear-shaped leaves.
- Curio repens (syn. Senecio serpens) — blue chalksticks (dwarf), a low, spreading mat of powdery blue fingers.
- Curio peregrinus (syn. Senecio peregrinus) — string of dolphins, a hybrid whose leaves curl into little leaping dolphin shapes.
Cultivation
Succulent Senecio / Curio are among the easiest succulents to keep, which is a large part of their popularity. Grow them in a gritty, fast-draining mix and give them bright light — plenty of indirect light indoors, or gentle sun with some shielding from harsh midday summer sun outdoors. Too little light causes trailing stems to stretch and the beads or leaves to space out and shrink.
Water thoroughly, then let the mix dry out before watering again; these plants far prefer to be kept a little too dry than too wet, and standing moisture quickly leads to rot. Growth patterns vary between species — some rest in the peak of summer heat, others slow through the cold of winter — so ease off watering whenever a plant is resting rather than to a fixed calendar. Keep them frost-free. See Watering and Repotting for general technique. Trailing species look their best cascading from a hanging pot or a shelf edge, where the stems can hang freely.
Propagation
These plants are very easy to propagate from stem cuttings. Snip a length of stem, let the cut end callus for a day or two, then lay it on or shallowly press it into slightly moist gritty mix — trailing species root readily where the stems touch the soil. Coiling a strand around the top of a pot and pinning it down is a reliable way to fill out a fuller, denser basket. See Propagation — cuttings for details.
Hobby and cultivar notes
The group is popular enough that variegated forms are widely traded, especially cream-and-green variegated string of pearls. Variegated plants carry less chlorophyll, so they grow more slowly, scorch more easily and need brighter (but not harsh) light to hold their colour — give them a touch more protection from direct sun than their all-green counterparts. Several of the "string of…" novelties, including string of dolphins, are hybrids selected for their leaf shape rather than distinct wild species.
A note on names: taxonomists have moved most of the succulent species out of Senecio into Curio (and a few into other segregate genera), but the horticultural trade has been slow to follow. You will encounter the same plant under both names, so both are worth searching when tracking down a particular species.
See also
- Curio — the segregate genus into which most of these succulents are now placed
- Curio rowleyanus · Curio radicans · Curio peregrinus
- Soil and potting mix · Watering · Propagation — cuttings · Repotting · Pests and diseases