String of Pearls

Season note

Allow soil to dry out between waterings; very drought-tolerant due to water stored in its 'pearls'.

Overwatering signs

Mushy, rotting pearls; crown rot

Underwatering signs

Shriveled, deflated pearls

Light level

bright indirect to some direct

Best rooms

Soil

Fast-draining cactus/succulent mix

Humidity

Low; no extra humidity needed

Fertilizer

Diluted balanced fertilizer once a year in summer

Temperature range

13°C – 24°C

String of Pearls, currently classified as Curio rowleyanus but long known and still commonly sold under its older name, Senecio rowleyanus, is native to the arid Cape provinces of southwestern South Africa, where it grows across rocky, drought-prone shrubland known as the Karoo, spreading into thick, low mats that cover exposed rock and thin soil. The plant belongs to the daisy family, Asteraceae, and its genus name honors the British botanist Gordon Rowley, who studied and popularized the species. Botanically, its classification has shifted in recent years: originally placed in the large and diverse genus Senecio, molecular research led to its reclassification into the newer genus Curio, though the older Senecio name remains extremely common in the nursery trade and among home growers, much like the parallel naming situation seen in calathea and its reclassification into Goeppertia.

The plant's most distinctive and immediately recognizable feature is, of course, its foliage: rather than flat leaves, String of Pearls produces small, nearly spherical, pea-sized leaves strung at intervals along thin, trailing stems that can reach two to three feet in length given time and favorable conditions. Each spherical leaf is a genuine water-storage adaptation, functioning much like the swollen leaves or stems of a more conventional succulent, allowing the plant to survive extended dry periods between rainfall in its native semi-desert habitat. In the wild, the plant's weak, shallow surface roots readily take hold wherever a trailing stem makes contact with soil, allowing it to spread and form dense ground-covering mats across the rocky terrain it favors — the same rooting behavior that, in cultivation, makes stem propagation so straightforward. Because it doesn't tolerate frost and is limited outdoors to roughly USDA hardiness zones 9b through 11b, String of Pearls is grown almost exclusively as an indoor houseplant across the vast majority of the world, even though it can be moved outside temporarily during warm, dry summer stretches in more temperate climates.