String of Pearls and the Other Trailing Succulents That Keep Dying

String of pearls — recently moved from Senecio to the genus Curio, so both names appear on labels — is a creeping succulent from arid parts of southern Africa. In the wild it does not hang. It sprawls across the ground and between rocks, rooting into the soil wherever a node touches, forming a mat in the partial shade of larger plants.

That growth habit explains almost everything about how it fails indoors. The stems are thin, the roots are shallow and fine, and the plant is adapted to a substrate that dries within a day or two. Hung in a deep pot of ordinary compost, the base stays wet for a fortnight, and the fine roots and the buried stem sections rot first — which is why these plants so often die from the centre outwards while the trailing ends still look fine.

The spherical leaves are the other distinctive feature. A sphere has the lowest possible surface area for its volume, which minimises water loss. Each pearl carries a translucent line — the epidermal window — that lets light into the interior of an otherwise opaque leaf. It is an elegant adaptation and it also means the plant is genuinely built for bright conditions, not the dim corners it usually ends up in.

Use a shallow, wide pot, and use terracotta if you can. The roots occupy only the top few centimetres, so anything deep is a reservoir of permanently damp medium sitting under the plant with nothing drawing on it.

The medium should be sharply draining and mostly mineral: about a third peat-free or cactus compost to two-thirds coarse grit, pumice or perlite. Standard houseplant compost, on its own, holds water far too long for this plant.

Hanging pots complicate matters, because you cannot see the medium easily and you are unlikely to lift the pot to feel its weight. If it hangs, take it down to water it, let it drain fully, and put it back — never water it in place with the saucer built in.

The plant is also fragile in a way that matters practically. Strands snap easily, and every broken strand is both a small wound and, incidentally, a free cutting. Site it where it will not be brushed past.

Give it bright light with two to four hours of direct sun — an east window, or back from a south or west one. Full unfiltered afternoon sun through glass can scorch the pearls, but too little light is by far the more common error and produces a distinctive result: long bare stretches of stem with small, widely spaced pearls.

Water thoroughly, then let the medium dry out completely. In a bright warm room that means roughly every two to three weeks in summer, and every four to six weeks in winter. The plant will not tell you it is thirsty until it is quite thirsty, and it recovers well from that; it does not recover from a fortnight of wet medium.

Read the pearls. Firm and round means well hydrated. Slightly shrivelled, with a pointed tip and a faint dimple, means it is ready for water and will plump up within a couple of days of a soak. Squashy, translucent, splitting or yellowing pearls mean too much water and, usually, rot already underway at the roots.

Feed very sparingly — half-strength cactus feed two or three times through the growing season. Overfeeding produces soft, elongated growth that never looks right.

This is the compensation for the plant's fragility: it propagates almost without effort, because rooting at the nodes is what it does in nature.

The simplest method is surface layering. Take a strand 10–20 cm long, coil it on top of barely damp gritty mix in a shallow pot, and press it gently so the nodes contact the surface. Do not bury it. Keep it in bright light, mist lightly every few days, and roots form at multiple nodes within two to three weeks.

You can also lay strands on the surface of the parent pot without cutting them at all, which is the fastest way to fill a thin, bald patch in an established plant. They root where they touch and thicken the crown.

Water propagation works but is a poor choice — the roots produced are adapted to water and struggle in a gritty mix afterwards. Surface layering into the medium the plant will actually live in is more reliable.

For a full pot from the start, lay six or eight strands rather than one or two. These plants look sparse for a long time if you begin with a single strand.

String of pearls produces small white brush-like flowers that smell distinctly of cinnamon, usually in late winter or early spring after a cool, dry rest. Keeping the plant cool — around 10–13°C — and nearly dry through the winter makes flowering considerably more likely, and it is the same regime that keeps the plant healthy anyway.

The three failures that account for nearly every dead plant are worth stating together, because they compound. A deep pot of water-retentive compost, a position with too little light, and watering on a weekly schedule will kill one within a season even though none of the three alone would be immediately fatal.

If a plant is dying from the centre, act fast rather than adjusting care. Lift the whole thing, cut away every soft or blackened stem and root, and take the healthy trailing ends as cuttings. It is nearly always possible to save the plant as cuttings even when the original crown is beyond rescue.

One safety note: Curio and Senecio species are toxic to cats and dogs, causing vomiting and drooling, and the trailing habit puts them exactly where a curious cat can reach. Hang them well clear, or choose Ceropegia woodii, which is not toxic.