Plant records · Direct sun
String of pearls: how to water a plant with no leaves
Curio rowleyanus has replaced its leaves with water-storing spheres, which means it has no way to shed water and no way to recover quickly from a wet pot. It also needs more light than almost any position indoors can offer. Nearly every dead string of pearls died of overwatering in insufficient light.
Curio rowleyanus · Asteraceae
| Botanical name | Curio rowleyanusAsteraceae |
|---|---|
| Light | 3,000-8,000 lxDirect sun |
| Humidity | 25-40% |
| Watering | Every 18 days |
| Drainage | Very free-draining: 40% cactus compost, 30% perlite, 30% coarse grit. This plant grows on rocky ground in the Cape and its roots are adapted to drying within hours. |
| Mature height | 90 cm |
| Growth rate | Fast when happy: a healthy strand grows 5-15 cm per month in summer and can reach 90 cm within a year. In low light it produces sparse, widely spaced beads. |
| Propagation | Lay a strand on the surface of dry gritty mix, pin the nodes down, and roots form in two to three weeks. Do not bury the beads — only the stem where a node touches the surface. |
| Pet safety | toxicToxic to cats and dogs. The spherical leaves are exactly the shape and size a cat will bat at and eat, and ingestion causes vomiting and lethargy. Hang it out of reach rather than on a low shelf. |
presentationWhat you are seeing
- Beads that go soft, translucent and mushy, starting where the strand touches the soil and moving outward. The strand collapses and the beads on the far end may still look fine for a few days.
- Beads that shrivel, flatten and develop a visible crease down the side, or that look deflated like tiny raisins.
- Long stretches of bare stem between beads, with visible gaps, on a plant that used to be dense.
aetiologyWhy it happens
- Mushy translucent beads spreading from the soil line is stem and root rot, caused by the mix staying damp. This plant's roots are fine and shallow and have essentially no tolerance for wet soil. The rot travels along the strand from the base outward, so the healthy-looking tip is a false signal.
- Shrivelled, creased, deflated beads are the opposite: genuine drought. Because the beads are the plant's water store, they visibly deflate before any other symptom appears. This is the plant's thirst signal and it is completely reversible.
- Wide gaps between beads mean insufficient light. The plant extends its stem to reach better light and produces fewer, smaller beads along the way.
managementWhat to do
- Distinguish the two problems before doing anything. Mushy = rot, shrivelled = thirst. They need opposite treatments and it is easy to kill a thirsty plant by treating it as if it were rotting.
- For rot: cut the strand well above the affected area — at least 5 cm beyond the point where the tissue is last firm — and discard the rotten length. Let the cut end callus for three days, then lay the healthy strand on fresh dry gritty mix. Do not water for a week.
- For thirst: water thoroughly until water runs out of the drainage hole, then wait until the beads are just beginning to show a faint crease before watering again. In summer, in bright light, that is roughly every 18 days.
- Give it 3,000-8,000 lx: a south or west windowsill with four or more hours of direct sun. Beads that are getting enough light are compact and round; beads in low light are elongated and oval.
- Pot it in a shallow, wide container rather than a deep pot. The roots are shallow and a deep pot holds a reservoir of wet mix the roots never reach. A 10 cm deep bowl is enough for a mature plant.
The bead is the water gauge
Because every leaf has become a water-storing sphere, the plant's hydration is visible from across the room. A well-watered string of pearls has beads that are plump, slightly glossy and round. As the plant uses its water the beads lose volume, developing a faint crease along the side, then flatten, then look like deflated raisins.
The useful watering point is at the faint crease. That is early enough to avoid stress and late enough to avoid wet roots. Watering when the beads are still plump is the single most common way to kill this plant.
Do not rely on the look of the mix surface. In a shallow bowl with a gritty mix, the surface can look dry while the layer 3 cm down is still damp. Judge by the beads, not the soil.
- Plump, glossy beads: do not water
- Faint crease along the bead: water now
- Flattened, deflated beads: water immediately, plant is stressed
- Mushy, translucent beads: rot, not thirst — do not water
- Summer in bright light: roughly every 18 days
Light and the shape of the bead
The bead shape is a direct readout of light level. In strong sun the spheres are almost perfectly round and tightly packed along the stem. In medium light they become slightly oval and the spacing widens. In low light they elongate into teardrops with long bare stretches between them.
This plant is not a candidate for a north window or a shelf away from the glass. It wants four or more hours of direct sun, ideally on a south or west windowsill, or outdoors in summer in a position that gets morning sun and afternoon shade.
Sun through glass in a west window in July can be intense enough to scorch the beads facing the glass. If you see bleached, papery patches on the sunward side, screen with a sheer for the hottest part of the afternoon.
Growing it in a hanging position without losing it
String of pearls is usually grown hanging, which makes it hard to inspect. The practical trick is to hang it at eye level or lower for the first year — on a hook above a shelf, or on the edge of a bookcase — so you can see the top of the pot and the point where the strands leave the soil. That is where rot starts and it is invisible from below.
Once the plant is established and you know its watering rhythm, you can hang it higher. Even then, take it down once a month and check the soil line for soft beads.
Troubleshooting
Half my strands have gone mushy at the top but the ends look fine. Can I save them?
The beads are shrivelled. Should I water?
Why do my beads have gaps between them?
CaveatCare information only. Toxic to cats and dogs if eaten — hang it out of reach and contact a veterinarian for suspected ingestion.
Published2026-10-16 ·