String of pearls care: water, light and soil

Light

Bright light keeps the beads tight along the stem. In the University of Illinois Extension scale, that means high light, about 300 foot-candles, which you get directly in front of an east or west window or up to five feet back from a south one. NC State rates it for partial shade outdoors, two to six hours of direct sun, while indoors it does best in bright, indirect light; Missouri Botanical Garden lists full sun to part shade for the garden.

Gentle morning sun is welcome. Hot afternoon sun through glass is not: NC State notes that direct sunlight can scorch the beads, leaving tan, dry patches on the exposed side. In a dim room the stems stretch, leaving long bare gaps between beads that never fill in. Hanging baskets often sit above window level, so check that the crown, not just the trailing ends, actually sees the sky.

Water

This is the part people get wrong, and the two main sources pull in slightly different directions. Missouri Botanical Garden says to let the roots dry between waterings and notes that the plant can withstand long droughts. NC State agrees that it tolerates infrequent watering but adds that you should never let it dry out completely. In practice, wait until the mix is dry well down into the pot, then water slowly at the soil surface, not over the strands, until it runs from the drainage hole.

Read the beads as a gauge. Firm, round beads mean the plant is fine. Wrinkled or flattened beads on dry mix mean it is thirsty. Wrinkled beads on wet mix, with soft dark stems at the soil line, mean rot, and more water will finish it. Because the roots are shallow and the stems sit right on the surface, a pot that stays damp near the top is far more dangerous than one that dries a little too far.

Cut back sharply in winter. Both sources advise a cool rest at 50 to 60°F, and at those temperatures the mix dries slowly, so you may water only a fraction as often as in July. Empty any saucer under a hanging pot within half an hour.

Soil and pH

Use a dry, sandy, very well-drained mix. Missouri Botanical Garden recommends a cactus-type potting mix, and NC State suggests either a cactus mix or regular potting soil blended with sand or perlite. Peat-heavy bagged mix alone holds water around the stem bases for too long. A shallow, wide pot suits the creeping habit better than a deep one, since the roots stay near the surface and a deep pot leaves a wet layer below them.

Humidity

Humidity is not a concern. The bead shape exists to cut water loss in arid air, so the dry air of a heated home in winter does no harm, and Missouri Botanical Garden notes that high humidity does not bother it either. Skip misting; wet beads and a damp crown only invite rot.

Temperature

Warm summers and cool winters match its native rhythm. NC State and Missouri Botanical Garden both give 70 to 80°F as the summer range and 50 to 60°F for winter. It is frost tender and outdoors is limited to USDA zones 9b to 11b, so a pot that summers on a porch must come inside before the first fall frost. Keep it away from heating vents, which dry the beads unevenly, and off glass that turns icy at night.

Fertilizer

It needs little food. No source gives a specific feeding rate for this plant, so follow the University of Illinois Extension rule for houseplants: no more than once every one to three months between March and September, with a balanced or 1:2:1 houseplant fertilizer at the label rate, never stronger. Stop in winter while it rests. Too much nitrogen gives soft, widely spaced beads that are more prone to rot.

Work out the dose for your watering can with the fertilizer dilution calculator →

Repotting

Missouri Botanical Garden suggests repotting every spring, and the reason is the mix rather than root space: fine organic potting soil breaks down and stays wetter each year, which is dangerous for a plant that rots easily. Lift the whole mat of stems carefully, since the beads snap off at a touch, and set it at the same depth in fresh, gritty mix. Go up only an inch or two in width.

Be realistic about age. Both sources say the plant tends to die back after several years. When the center thins and new growth stalls despite good care, propagate the healthiest strands instead of nursing the old crown.

• Stems have filled the rim and new growth is thin
• The mix stays wet for days or has broken down
• Bare patches appear in the center of the pot

Propagation

Stem cuttings root fast. NC State recommends taking 3 to 5 inch pieces and covering a few nodes with potting mix, where new roots form. A simpler trick is to coil the cut strands on top of a pot of barely damp cactus mix and pin them down with a bent paper clip; roots grow wherever stem touches soil, just as the plant creeps in the wild. Spring and summer, when it is growing, give the quickest results.

A single bead dropped on the soil can root too, but NC State calls this slower and less reliable. Outdoors the plant also sets seed with a cottony pappus carried by wind, though indoor plants rarely bloom; when they do, the small white flowers smell of cinnamon.

Methods: Stem cuttings laid on mix, Single beads dropped on the soil (slow) · Best season: spring to summer.

Common problems

Most failures come back to water, light or age. Shriveled beads are the classic complaint, and Missouri Botanical Garden lists all three causes for them: overwatering, underwatering and poor light. Check the mix first. NC State adds that leaves turning yellow or gray may point to insects, and names aphids, whiteflies, fungus gnats, ants and mealybugs. Fungus gnats in particular signal a mix that stays too wet.

Not sure which one it is? Try the plant problem diagnosis tool →

Is the string of pearls toxic to cats and dogs?

The ASPCA has no entry for string of pearls under any of its names in its cat and dog plant lists, so the ASPCA neither confirms nor rules out harm. NC State does rate it: a problem for cats, dogs and horses, with low poison severity for people, pyrrolizidine alkaloids as the toxic principle, and vomiting, diarrhea and skin irritation as the symptoms. Several other Senecio species, such as groundsel and ragwort, are listed as toxic by the ASPCA. Hang the pot well out of reach of pets, wear gloves when handling broken stems, and call your veterinarian or the ASPCA Animal Poison Control Center at (888) 426-4435 if a pet chews it.

Check any other plant against the ASPCA lists →