String of Pearls (Curio rowleyanus) are remarkable aromatic succulents prized since ancient times for their beautiful, pearl-like foliage and spicy cinnamon-scented white flowers.
Native to Southwest Africa, these plants grow wild on the ground in nature, creating a thick ground cover only a few inches tall.
When potted, however, their trailing stems can grow up to 3 ft. (1 m.) long, forming a charming cascade of succulent, spherical leaves 0.5 in. (1.25 cm) in diameter.
Other common names for String of Pearls include String of Beads, String of Peas, Bead Plant, Rosary Vines, String of Marbles, and Irish Beads.
String of Pearls Care
String of Pearls are very popular and easy-going plants, similar to other succulents.
However, they may prove a bit challenging for the inexperienced beginner. Improper care may cause the beads to easily shrivel or turn mushy.
For best care, follow the tips below on everything from soil care to proper propagation techniques, and more.
Soil
Like other succulents, String of Pearls require fast-draining, chunky, aerated soil such as cactus potting soil mix. If you only have regular potting soil, mix with ⅓ part sand to simulate natural sandy soil.
Watering
The leaves on String of Pearls retain a lot of moisture so infrequent watering (once every 2 weeks) is best.
From spring through autumn, the soil can be kept slightly moist as they need the extra water to grow. In winter, however, allow the soil to dry out completely between waterings.
Signs of underwatering are flat and dry leaves; whereas, overwatering will cause leaves to turn mushy.
Lighting
2-4 hours of direct, bright, early morning sunlight in a south-facing window year-round is ideal.
For hotter climates and summertime, 6-8 hours of indirect, diffused, and partial sunlight is best.
Humidity & Temperature
Low to medium humidity (40-50%) or average room humidity is ideal.
In humid climates, ensure proper ventilation and avoid misting as excessive moisture can attract pests and damage leaves.
In colder, dry climates, grouping your plants together or using a humidifier helps maintain moisture.
String of Pearls grow best at temperatures ranging from 64-74°F (18-24°C). In the winter, keep temperatures from falling below 50°F (10°C).
Fertilizing
During spring through fall (growing season), feed every 2 weeks with a balanced liquid fertilizer diluted at half strength. In winter, feed every 6 weeks (or forgo entirely).
If avoiding chemicals, use light composting such as worm castings , fish emulsions, tea leaves, or coffee grounds.
Propagation
In early summer, clip off a section (~4 in/10 cm) of stem and pearls, and place them in damp potting soil until the beads are almost covered.
In 2-3 weeks, new roots will easily form from the places where the beads join the stem.
Diseases & Pests
Sap-sucking aphids or mealybugs are a curse to the String of Pearls. For signs of infestation, look for off-colored yellow pearls and white powdery substances, which feed sooty black mold. For pest treatment, use insecticidal soap and rinse well with water.
Overwatering may also attract fungus which cause root rot. Use fungicide (or natural neem oil) to treat. If heavily diseased, use a sharp knife to cut away black and diseased roots, sterilizing between each cut. Re-pot in a terra-cotta or clay pot to better drain soil.
Toxicity
Moderately toxic, String of Pearl leaves are poisonous to humans and pets if consumed. Signs your pets have ingested leaves include vomiting, diarrhea, drooling, or lethargy.
String of Pearls vs String of Tears
String of Pearls and String of Tears are easily confused, as both have bright green spherical pods and trailing stems. However, String of Tear leaves resemble tear-drops, pointing upward with distinct vertical tips vs. String of Pearl leaves, which are more spherical (without tips).
String of Pearl stems are also bigger (up 3 ft./1 m) vs. String of Tear stems, which grow to only ~1.6 ft. (50 cm).
Frequently Asked Questions
To ensure thicker-looking pearls, coil a few stems around the top of the plant, or take a few cuttings and return to soil. These will eventually take root, making your plant look fuller. Pruning dead stems or pearls with sterilized scissors will also promote bushier plants.
Re-pot annually (or every two years for mature plants) to prevent poor soil, improve air flow, and improve nutrition.
String of Pearls are robust growers which quickly cover the surface of their pots before developing stems that hang from the sides. Stems grow between 5-15 inches (15-40 cm) per year and grow up to 3 ft. (1 m.) long.
The best way to tell if a String of Pearl plant is dying is via the quality of its pearls. Monitor the leaves and take appropriate action to prolong life.
Flattened, collapsed pearls are signs of underwatering. Burst, mushy, and shriveled pearls are signs of excessive hydration, which invite pests, root rot, and eventual death.
Prune dead stems and leaves, and re-pot in terra-cotta or clay pots to ensure soil drainage. Make sure pots are not too big for the plants and keep soil level high (1 inch from rim) to ensure adequate aeration.
Leggy stems, and scattered pearls are signs of inadequate sunlight, while scarred and dry pearls are signs of sun overexposure. Falling pearls are common in the winter when temperatures drop too low.