String of Pearls

How to care for String of Pearls

Light

String of Pearls performs best in bright, indirect light for most of the day, such as a position close to a south- or east-facing window screened by a net curtain. A few hours of gentle morning sun is beneficial and encourages compact growth, but harsh afternoon sun can scorch the delicate bead-like leaves. Insufficient light leads to elongated, widely spaced beads and weak, trailing stems. Supplementary grow lights are useful during the short days of a British winter.

Watering

This species is highly susceptible to root rot and must be watered sparingly. Allow the potting mix to dry out completely between waterings, checking several centimetres into the soil before adding more water. Water thoroughly until it drains from the base, then empty the saucer to prevent the roots sitting in moisture. In winter, when growth slows, watering should be reduced to once every three to four weeks or even less. Underwatering causes the beads to shrivel slightly, which is a recoverable state; overwatering usually results in fatal root rot.

Soil and potting

A very free-draining mix is essential. A proprietary cactus and succulent compost, ideally amended with 20 to 30 per cent horticultural grit or perlite, suits this plant well. Heavy or peat-based potting composts retain too much moisture and increase the risk of rot. Good drainage holes in the pot are non-negotiable, and unglazed terracotta pots are preferable to plastic because they allow the growing medium to dry more evenly.

Feeding

Feed once a month during the active growing season from April to September using a balanced liquid fertiliser diluted to half the recommended strength, or a fertiliser formulated specifically for succulents. Do not feed during autumn and winter when the plant is resting. Over-feeding encourages soft, weak growth and can damage the root system.

Humidity and temperature

Curio rowleyanus is well adapted to low humidity and grows comfortably in the dry indoor air typical of centrally heated British homes. Avoid placing it near humidifiers or in bathrooms with persistent condensation, as excess moisture promotes fungal disease. It prefers temperatures between 13 and 27 C and can tolerate brief dips to around 10 C, but frost will kill it. Keep it away from cold draughts, radiators, and air-conditioning vents.

Repotting

Repot infrequently, as the plant prefers to be slightly pot-bound and excessive root disturbance can cause stress. When the roots begin to emerge from the drainage holes or growth appears significantly congested, move the plant up by one pot size, typically in spring. Take care when handling the brittle stems, and allow the plant to settle without watering for several days after repotting to let any damaged roots heal.

Pruning

Pruning is straightforward and mostly undertaken to manage length or to remove dead, shrivelled, or diseased sections of stem. Cut back leggy stems with clean, sharp scissors to encourage bushier growth from the base. Pruned stem sections can be used as cuttings for propagation. Remove any fully bare or rotted stems promptly to prevent the spread of disease.

Is String of Pearls toxic?

Common problems

How to propagate

Stem cuttings

Take a healthy stem section 8 to 15 cm long, remove the beads from the lower 2 to 3 cm, and allow the cut end to callous for one to two days. Lay the bare section on top of, or just below, the surface of barely moist succulent compost and keep in bright indirect light; roots will typically form within two to four weeks.

Layering

Pin a section of stem onto moist succulent compost in a separate pot while still attached to the parent plant. Once rooting is visible and new growth begins, sever the connecting stem. This method maintains a supply of moisture to the cutting during rooting and tends to produce a high success rate.

Where String of Pearls comes from

Native to southwestern Africa, Namaqualand (South Africa), southern Namibia.

Story and origins

The genus name Curio is derived from the Latin word for 'curiosity', reflecting the unusual and distinctive appearance of the plants within this group. The species epithet rowleyanus honours Gordon Douglas Rowley (1921 to 2019), a British botanist and leading authority on succulent plants who contributed extensively to the classification and documentation of the Crassulaceae and Asteraceae succulent genera. The widely used common name String of Pearls is a straightforward allusion to the bead-like leaves strung along slender stems, resembling a pearl necklace.

Curio rowleyanus was first formally described for science in 1922 by the German botanist Conrad Gürke, who placed it in the genus Senecio as Senecio rowleyanus. It is native to a relatively small area of south-western Africa, principally Namibia and the Northern Cape of South Africa, where it inhabits rocky, semi-arid slopes and grows in the partial shade of scrub vegetation. The plant entered widespread cultivation during the latter half of the twentieth century as the popularity of succulents as houseplants grew. Its dramatic trailing habit made it particularly sought after for hanging baskets, and by the early 2000s it had become one of the most recognisable and commercially traded trailing succulents worldwide. Despite this popularity, it remains somewhat challenging to keep long-term, and mature, full specimens are considered a mark of a skilled succulent grower.

Varieties to know

Curio rowleyanus 'Variegatus'

A variegated form with beads marked in cream or pale yellow alongside green. More difficult to grow than the species due to reduced chlorophyll content.

Curio rowleyanus 'Big Bead'

A selection with noticeably larger, rounder beads than the standard species, giving a bolder appearance in hanging baskets.

Fun facts

• The spherical leaf shape is an evolutionary adaptation to minimise surface area and reduce water loss in the dry, semi-arid conditions of its native habitat.
• Each bead possesses a narrow translucent stripe called an epidermal window or 'leaf window', which allows sunlight to reach the internal photosynthetic tissue without the entire leaf surface being exposed to drying sun.
• The plant produces small, white, daisy-like flowers with a spicy, cinnamon-like fragrance that is notably stronger than one might expect from such an unassuming bloom.
• In the wild, Curio rowleyanus spreads by creeping along the ground and rooting at stem nodes, forming dense mats in the partial shade beneath shrubs rather than trailing as it does in cultivation.
• The genus Curio was separated from Senecio in 2001 following molecular phylogenetic studies, meaning many older references and plant labels still list this species as Senecio rowleyanus.

String of Pearls FAQ