String of Pearls Curio rowleyanus

The String of Pearls is a succulent vine that is popularly grown as an ornamental in hanging baskets in the United States. The plant has tiny pea-shaped leaves that grow on trailing stems that spill downward like a string of pearls over the side of the planter. The rounded, fleshy leaves of String of Pearls are unique, each resembling a pearl, a bead, or a marble.  It can be grown both indoors as a houseplant or outdoors in a more tropical location.  It is limited to outdoor use in the USDA Hardiness zones 9B through 11b; therefore, it is mostly grown as a houseplant. The mature size is 1 to 2 feet tall and 1 to 2 feet long. This plant is toxic to both humans and pets.

The plant is native to the dry areas of South Africa where it will grow in a vine-like manner. It creeps and crawls along the ground, and roots are formed wherever the plant comes in contact with the ground.  It often grows under bushes and rocks. 

The previous synonym for the plant was Senecio rowleyanus. The genus name, Senecio, is Latin for the word senex which means "old man from the hoary pappus."  This plant was recently moved to the genus Curio which means "curiosity." The specific epithet, rowleyanus, honors Gordon Douglas Rowley, a British botanist whose specialty was succulents and cacti.  

If planted outdoors, it should be in locations that include partial shade; whereas, indoor plants flourish in areas where they receive bright, indirect sunlight. Cactus potting mix or a combination of potting soil mixed with sand or perlite is an ideal planting or container medium. It is intolerant to frost and must be brought indoors before the first fall frost. It tolerates infrequent watering, but overwatering can result in root rot. Never allow your plant to completely dry out between watering.  Warm temperatures of 70 to 80 degrees during the summer and cool temperatures of 50 to 60 in the winter are best.

These plants tend to die back after several years. Propagate by stem cuttings instead of trying to revive the older plant. Propagation can be easily and quickly accomplished by taking a 3 to 5-inch stem cutting and covering a few of the nodes in the potting mixture  This will allow new roots to form.  A slower and less reliable form of propagation can be done by simply dropping a leaf onto your soil mixture. The wind disperses the seeds after outdoor plants flower. 

The rounded shape of the leaf decreases the amount of surface area exposed to the arid desert air; therefore, reducing the loss of water or moisture. There is a dark band on the side of the leaf that is an epidermal window. This small slit of translucent tissue allows light to penetrate the inside of the leaf. This increases the available area where photosynthesis can take place.  

Consider this unique ornamental succulent for a houseplant or hanging basket to add interest to your indoor garden or patio. Beware that the plant's leaves and sap are slightly toxic. Avoid ingestion and wear protective gloves to prevent skin irritation. Monitor small children and pets.

Seasons of Interest:

Bloom:  Summer, rarely flowers indoors     Foliage: Year-round

• succulent vine with trailing stems, 1 to 2 feet tall and 1 to 3 feet long at maturity
• tiny, green, pea-shaped leaves about 1/4 to 1/3  inch in diameter with a small pointed tip, and a thin strip of darker green on the side of the leaf
• flowers are white, daisy-like, 0.5 inches in diameter, long red stamens, bright yellow stamens on 1.5-inch long peduncles
• flowers have a cinnamon scent
• fruits are multiple seeds that have a white cotton-like pappus

Insects, Diseases, and Other Plant Problems:  Monitor for aphids, whiteflies, gnats, ants, and mealybugs. Soggy wet soil will result in root rot and the plant's demise. This plant is very particular about its growing conditions. It does not tolerate being overwatered, underwatered, or having inadequate light. Wilting leaves can occur from underwatering or overwatering. Yellow or graying leaves may be caused by insects. Scorching of the leaves can occur from direct sunlight.