The string of hearts plant is a tender perennial native to Zimbabwe and South Africa. It is easily recognized by its heart-shaped leaves and trailing habit. It is a member of the Asclepiadaceae family and the genus Ceropegia, and also is known as rosary vine, hearts on a string, and hearts entangled. While it is a very common houseplant, it will only survive outdoors in tropical climates.
The leaves of these houseplants are unusual, having a blue-green color streaked with silver on the topside and a purplish or gray underside. They grow oppositely down slender stems, often trailing for 3 feet (91 cm) or more over the sides of hanging planters. Younger plants will not often flower, but those that are a few years old will produce tan or peach-pink flowers that resemble tiny lanterns or vases.
String of hearts plants are very easy to grow and require no more than sunlight and occasional watering. They are a good first plant for children and for those who have never kept houseplants. They are succulents, so they do not do well if over-watered, and the roots will rot if the plants are left in standing water. For best results, they should be allowed to dry out before they are watered. These plants go dormant during the winter and will require very little water during this time.
When growing wild in their native Africa, these vines are not climbers but trail along the ground. String of hearts plants are known for their ability to survive neglect and very dry soil; even if they wither from extreme drought, they will quickly recover when deeply watered. New top growth and fullness will be encouraged if some of the vines are occasionally cut back. They look best when they are crowded into a container that is slightly too small.
These houseplants can be propagated by separating the small, bead-like tubers that grow just below the base of the leaves. Each bead can be transplanted to create a new plant and, if they are simply pushed into the soil, they will form new plants while still connected to the original plant. These can then be removed and re-potted to form numerous new vines. While this is the quickest, most efficient way to grow new string of hearts plants, stem cuttings will also root well.
String of hearts are tough plants with a long lifespan. They may even be handed down through generations, becoming family heirlooms. All parts of the plants are poisonous, so they should be placed in an area where they are out of the reach of children and pets.