String of pearls

String of pearls trails over rock and through the shade of taller shrubs in the dry southern parts of Africa, rooting wherever a strand touches the ground. The beads are leaves, folded almost into spheres to hold water and cut down the surface the sun can reach, with a translucent stripe along one side that lets light into the middle. It is a beautiful plant and a genuinely unforgiving one, not because it needs much but because its roots are so shallow that a fortnight of wet compost is fatal. It was moved out of Senecio into Curio and most labels still use the old name.

Light

Several hours of bright light a day, including some gentle direct morning sun. An east window is close to ideal, and a bright hanging position near a window suits it better than a dark corner of the same room.

In poor light the plant does not simply slow down, it changes shape. The gaps between the beads lengthen, the strands become thin and sparse, and what should look like a curtain of green beads looks like string with occasional decorations. That growth does not tighten up again, so the fix is more light now and a hard cut back in spring.

Water

Soak the compost thoroughly, then leave it alone until it is dry all the way through. In a bright warm room that is roughly a fortnight in summer, and about a month in winter. Water into the compost rather than over the strands, and never leave the pot in a full saucer.

The margin here is narrower than for other succulents. The roots sit in the top few centimetres of the pot, so they are the first thing to sit in water and the first thing to rot, and rot at the crown takes whole handfuls of strands with it. If you are unsure, wait a few days. A wrinkled string of pearls recovers from one good soak; a rotted one has to be started again from cuttings.

Feeding and repotting

Two or three weak cactus feeds across spring and summer is enough, and none from autumn onwards. Repot every third year at most, in spring, into a shallow pot or a hanging pot with a good drainage hole. Depth is wasted on roots this shallow and simply holds wet compost underneath them.

Pruning and propagation

Cut back thin or bare strands in spring, and use everything you remove. This is the easiest succulent to propagate and the technique is unusual: lay a length of strand flat on the surface of dry gritty mix, hold it down here and there with a bent paperclip, and it roots at every node that touches. A pot topped up this way fills out in a season.

Cut pieces work too. Take lengths of about ten centimetres, remove the lowest few beads, let the cuts callus for two days, and press the bare ends into the mix. Either way, water sparingly until you can see new growth.

Flowers

A well grown plant flowers in late autumn or winter, and the flowers are worth waiting for. Each one is a small white brush of stamens on a short stalk, and they smell of cinnamon. They come on plants that have had a bright summer and a dry, cool autumn with almost no water, which is the same treatment that keeps the strands tight, so the flowers are a fair sign you have the light and the watering right.

Ailments

Wrinkled beads on dry compost mean thirst and one soak fixes them. Wrinkled beads on damp compost mean the roots have gone and the plant needs cutting up and restarting. Long gaps between beads are a light problem. Mealybugs hide where the strands meet the crown, which is also where rot starts, so it is worth parting the strands and looking every few weeks. The ledger below has the rest.