Houseplant · Apocynaceae
String of Hearts
Ceropegia woodii
Silver-marbled hearts strung on fine, threadlike stems that trail down for years.
Bright indirect
59–86°F · 15–30°C
USDA 10–12
3–12 ft · 0.9–3.7 m
Overview
String of hearts trails on stems as fine as thread, each strand lined with evenly spaced pairs of small heart-shaped leaves. Every leaf is a flat little valentine, slightly fleshy from the water it stores, its surface marbled silver over a deep green. Left alone, the strands lengthen to several feet, so the hearts run in long ranks from the stem tips down to the soil.
The succulence shows in the feel of it. Water sits stored inside the plump leaves and along the wiry stems, giving the foliage a firm, taut body that shrugs off a dry spell but turns soft and mushy in a wet pot. In bright light and a gritty, fast-draining mix, the strands push out fresh leaves quickly through spring and summer.
Light writes itself across the leaves. Under bright indirect light the hearts stay small, tightly spaced, and boldly marbled; starved of it, they fade pale and space out along bare, stretched stems. Give it that light and a dry-out between waterings and the plant holds its patterned foliage for years, each vine ready to root into more.
Care
The short version: bright indirect light for tight, well-marbled hearts, a free-draining cactus or succulent mix, and water only once the soil has dried out completely, with less through winter dormancy.
Light
Give it bright indirect light, as strong as you can manage short of harsh midday sun. Under a west- or south-facing window the leaves stay small, close-set, and richly marbled in silver. In a dim corner the hearts pale and space out along stretched, bare stems.
Water
Let the soil dry out completely between waterings, then soak it through, since the fleshy leaves and stems hold their own water and rot when the pot stays wet. Through winter dormancy the plant barely drinks, and the leaves stay plump on very little.
Soil
Root it in a free-draining cactus or succulent mix, sharpened with coarse sand or perlite so water runs straight past the tubers. It takes a wide pH range from 6.0 to 8.0, so drainage matters far more than the exact reading.
Temperature
Ordinary room warmth keeps the foliage firm and growing, anywhere from 59°F to 86°F (15°C to 30°C). Hold it above 60°F (16°C) in winter and away from cold drafts, since the fleshy leaves have no tolerance for frost.
Humidity
Plain household air keeps the leaves in good shape, and low humidity is no problem for foliage this succulent. There is no misting to do and no humidity reading to watch.
Feeding
Through the spring and summer growing season, a half-strength balanced houseplant fertilizer feeds the new leaves, once a month at most. Feeding stops entirely in winter while the plant rests.
Pruning
Trimming back the longest or barest strands pushes the plant into fuller, denser growth with more hearts packed along each stem. Every cut piece roots easily into a new plant.
Repotting
The tubers and roots like to be crowded, so repot only when you must. The signs are roots filling the pot, soil that dries almost as soon as you water, and growth that has stalled.
Size & spacing
35–144 in (90–365 cm) tall
Troubleshooting
Almost every problem shows up first in the look of the plant: the spacing of the hearts, their color, or the firmness of the stems. Too little light and too much water are the two causes behind nearly all of it. Match what the foliage is telling you below.
Yellowing leaves with soft, mushy stems at the base
Leaves turning yellow above stems gone soft and mushy is root rot from overwatering, the one failure that kills this plant. Soil kept wet leaves the lower stems squishy and the roots brown and slack. Stop watering, let the mix dry out fully, and repot into a free-draining cactus or succulent mix with the rotted tissue cut away. A few healthy cuttings or firm tubers set aside make a backup if the rot has spread.
Fix:
- Stop watering and allow the mix to dry out completely
- Repot into a free-draining cactus/succulent mix and remove rotted tissue
- Take healthy stem cuttings or tubers as backup if rot is advanced
Sticky film, twisted leaves, or specks moving on the vines
A sticky film on the leaves or warped, twisted new growth usually means aphids, mealybugs, or scale are feeding on the plant. Look for white cottony tufts, small raised bumps, or clusters of soft-bodied specks along the stems and the undersides of the hearts. Wipe them off with a cotton swab dipped in isopropyl alcohol, treat with insecticidal soap, and keep the plant apart from the others until the foliage is clean.
Fix:
- Wipe off pests with a cloth or cotton swab dipped in isopropyl alcohol
- Treat with insecticidal soap as needed
- Isolate the plant to prevent spread
Long, bare stems with wide spaces between the hearts
When the hearts drift far apart on long, naked stems, the plant is short on light. The leaves come in pale and thinly marbled instead of crisp silver, and the stems stretch on with few of them. A brighter window with bright indirect light tightens the spacing, and trimming the stretched strands brings denser, better-patterned growth.
Fix:
- Move to a brighter spot with bright indirect light, such as a west- or south-facing window
- Trim leggy growth to encourage denser branching
Toxicity
String of hearts is widely regarded as non-toxic and safe around cats, dogs, and the rest of the household. The stems and leaves carry a milky sap that can leave sensitive skin a little itchy, so wash your hands after taking cuttings, but a curious nibble is nothing to worry about.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
String of hearts is regarded as non-toxic, so a cat that bites off a heart or two comes to no harm. Any houseplant eaten in quantity can bring on a little drooling or a short stomach upset, but nothing serious follows.
Dogs None
Dogs are unharmed by this thin-stemmed vine. It holds no known toxin for them, though chewing the fleshy stems may cause mild, passing stomach upset, as any non-food plant can.
Horses None
Horses have no toxicity to fear from this plant. It is a small indoor vine they would rarely reach, and it contains nothing harmful to them.
Rabbits None
Rabbits are safe beside string of hearts. The leaves carry no poison, so a stray bite does no harm, though keeping the trailing strands out of reach spares the plant.
Livestock None
Grazing animals are in no danger from this plant, which lives indoors in a pot well away from any pasture. Nothing in its stems or leaves is toxic to them.
Birds None
Pet birds can perch and peck around this vine safely, since it holds no toxin known to harm them. An occasional nibbled heart is no cause for alarm.
People None
String of hearts poses no real danger to people. The stems and leaves ooze a milky sap that can leave sensitive skin a little itchy, so wash your hands after taking cuttings, and it is not something to eat.
As with any houseplant, discourage pets and children from chewing the foliage, and the milky sap of Apocynaceae plants may cause mild irritation in some individuals.
Varieties
Most growers keep the plain silver-marbled species, but one named form stands out by its coloring.
Ceropegia woodii 'Variegata'
A variegated form with hearts washed in pink, cream, and green, slower to lengthen than the plain silver species.
How to propagate
Every part of the trailing vine can start a new plant. A cut stem, a single bead-like tuber pressed to the soil, or a strand layered while still joined to the parent will each root into new plants.
Stem cuttingsEasy
Active growing season (spring to summer) · A few weeks to root, especially with bottom heat
A cut stem is the simplest start. Taken in the active growing season through spring and summer and pressed into a free-draining mix, the bare end puts out roots within a few weeks. A little bottom heat underneath speeds the rooting.
Offsets & pupsEasy
Active growing season · A few weeks once in contact with soil
Along the vines sit small, bead-like aerial tubers, the round tubercles that give the rosary vine its name. Set one on the soil surface during the growing season and it roots where it touches, lifting a new plant within a few weeks.
LayeringEasy
Active growing season · A few weeks
Layering roots a strand before it is cut. Pinned against the soil while still joined to the parent, a trailing stem grows roots from its tubercles over a few weeks of active growth, and the new plant is then snipped free.
Myths
String of hearts must be watered often to keep its leaves plump, the way a leafy houseplant is.
Those plump leaves are a water store, not a sign of thirst: this is a drought-tolerant semi-succulent that wants to dry out completely between drinks. Overwatering is what kills it, softening the stems and rotting the roots past saving. Once winter dormancy sets in and growth stops, the plant needs even less.