String of Nickels

About

String of nickels trails in long, fine threads strung with pairs of small, round, flat leaves, each one like a little coin, which is where both the common name and the species name nummularia, meaning coin-like, come from. New leaves and stems often have a silvery, waxy sheen.

It is an epiphyte, growing on the branches of trees in the wild instead of in soil, and a relative of the wax plants such as hoya. Like them it needs an airy root run, warmth and humidity instead of a rich, wet compost.

It makes a delicate hanging plant, its coin-strung threads spilling over the pot edge, and it is happiest in a warm, humid, bright spot such as a bathroom or a plant case.

Appearance and character

Leaves are small, round and flat, held in pairs along the trailing stems, mid green and often silvery and waxy when young, giving the strings of coins their name.

Stems are fine and thread-like, trailing down thirty to ninety centimetres, rooting here and there along their length where they touch a surface, as an epiphyte does on bark.

Flowers are tiny, cream or yellowish, tucked among the leaves, and are easily missed. The plant is grown for its trailing strings of leaves.

As an epiphyte it takes much of its moisture from humid air and rain instead of from soil, so it needs an open, fast-draining root run and high humidity.

Where it is from

Dischidia nummularia grows across Southeast Asia and the Pacific islands, perched on the branches of trees in warm, humid, lightly shaded rainforest. It roots in moss and bark instead of in the ground.

Give it warmth, high humidity, bright filtered light and an airy root run. It has no tolerance for frost, heavy wet soil or dry room air.

How it grows

It grows in warmth and humidity, trailing its coin-strung threads and rooting along them, and slows in the lower light and drier air of winter. Given warm, humid, bright conditions it grows steadily.

Pot it in a very free-draining, airy mix, such as orchid bark with a little compost and perlite, or grow it mounted, in a hanging pot where the threads can trail. Water when the airy mix is nearly dry, and never leave it soggy.

Keep it warm, above about 13 deg C, humid, and in bright indirect light. It suits a bathroom, a kitchen or a plant case where the air stays moist.

Take stem cuttings to propagate, which root readily in an airy mix or sphagnum, the same way as its wax-plant relatives.

Through the seasons

Spring brings renewed growth as light and warmth increase, the time to repot or take cuttings and resume feeding.

Summer is the main growing season in warmth and humidity. Water when the mix is nearly dry and keep the air moist.

Autumn growth slows as light falls. Reduce feeding and watering as the season turns.

Winter the plant rests in lower light. Keep it warm, humid and on the dry side, and protect it from cold draughts.

Care difficulty

Moderate, and easy once its epiphytic needs are met. Given warmth, humidity, bright light and an airy root run it grows steadily and needs little. The pitfalls are heavy, wet compost, which rots it, and dry room air, which shrivels the leaves. Grow it like a wax plant: airy, warm and humid.

Watering

Water when the airy mix is nearly dry, giving enough to moisten the roots and letting the excess drain straight through. As an epiphyte it dislikes sitting wet far more than a short dry spell.

Remember that the plant gets some moisture from humid air, misting or a humid spot, so do not make up for dry air with heavy watering. In winter, water less. Empty any saucer after watering.

Warning signs, diseases and pests

Mealybugs hide among the leaves and along the stems as white woolly tufts. Dab them off or treat with horticultural oil, checking where the paired leaves join the stem.

Root rot follows heavy, wet compost, showing as blackening, collapsing stems. Move the plant into an airier mix, water less, and keep it warm. Healthy cuttings will restart it if much is lost.

Shrivelled, thin leaves usually mean the air is too dry or the plant has been left too dry at the root. Raise the humidity and water a little more often.

Growing environment

Bright, indirect light suits it, matching the filtered light of the forest canopy. Direct sun scorches the small leaves, and deep shade thins the strings.

Warmth and humidity are essential, as for other epiphytes. Keep it above about 13 deg C and raise the humidity with a case, a pebble tray or a humid room, since dry air shrivels the leaves.

Give it a very airy, free-draining mix or a mount, and a hanging position where the threads can trail. A warm, humid bathroom or a plant case suits it well.

Feeding

Feed monthly through spring and summer with a dilute balanced or orchid fertiliser, since the plant takes little from its airy mix. Ease off in autumn and stop in winter.

Feed at half strength or weaker, as an epiphyte with fine roots, and flush the mix occasionally to clear any build-up.

Troubleshooting

The leaves are shrivelling. Usually dry air, or the roots left too dry. Raise the humidity with a case or humid spot, and water a little more often. As an epiphyte it takes moisture from the air as much as the roots.

The stems are collapsing and blackening. Rot from heavy, wet compost. Move it into an airy, bark-based mix, water less, keep it warm, and restart from healthy cuttings if needed.

Can I grow it mounted like an orchid? Yes. As an epiphyte it grows well mounted on bark or in an airy basket, kept humid, which suits its natural habit better than a pot of heavy compost.

There are white woolly tufts among the leaves. Mealybugs. Dab them off or treat with horticultural oil, checking where the paired leaves meet the stem.

Is it safe around pets? Yes. Dischidia is not recorded as toxic and is a relative of the non-toxic wax plants, so it is a safe trailing plant for a home with animals.