Aluminium plant

Aluminium plant: how do you recognise it?

Habit

Upright, branching little plant 30–40 cm tall and wide, with succulent stems.

Leaves

Opposite, oval, 5–8 cm long, slightly quilted and finely toothed, dark green with silver patches between the veins.

Silver

The silver pattern comes from thin layers of air under the leaf’s skin, not from a pigment.

Flowers

Small, inconspicuous greenish-white flowers in clusters in the leaf axils; they are hardly noticed.

Stem

Becomes bare and somewhat woody at the base over the years; that is the time to take cuttings.

Plants: March–April · Pruning: March–August

Why grow it?

• Silver-marked leaves that look good all year and brighten up a group of green plants.
• Small and compact: ideal for a windowsill, a shelf or a desk by the window.
• Grows fast and forgives a forgotten watering.
• Very easy to root: a few shoot tips in a glass of water give you new plants.
• Also suits an open terrarium or bottle garden with other small foliage plants.

Aluminium plant: where does it grow best?

• Light without fierce sun: by an east- or west-facing window, or a little way back from a south-facing one. Fierce sun scorches the leaves; too little light makes it long and floppy.
• Room temperature of 18–24 °C; in winter not below 12 °C.
• Moderately humid air: a tray of wet gravel or a group of plants helps against dry air and spider mite.
• No cold draughts and no spot directly above a radiator.

Light

Bright, out of direct sun

Potting soil

Multi-purpose compost or airy, humus-rich compost

Acidity

Acid or neutral

Watering

Moderately

Size

0.4 m tall, 0.4 m wide

Temperature

Minimum 12 °C

Goes well with

• Nerve plant: Finely veined leaves with the same needs; together ideal in an open terrarium.
• Peperomia: Small, compact foliage plants in green and red for the same bright spot.
• Boston fern: Fresh, fine green fronds that show off the silver pattern.
• Calathea: Patterned leaves for the same spot out of fierce sun.

Aluminium plant: when and how to plant it?

Plant in March–April.

1. Repot in March or April when the pot is full of roots, usually every year or every other year.
2. Choose a wide, fairly shallow pot with a drainage hole; the roots stay shallow.
3. Use open houseplant compost mixed with some perlite.
4. Set the plant at the same depth as before, fill in and firm lightly.
5. Water until it runs out of the bottom and empty the saucer after a quarter of an hour.
6. For a fuller plant, pot three to five young rooted cuttings together in one pot.

Care

Watering

Keep the compost lightly moist and let the top centimetre dry out between waterings. Use room-temperature water; wet feet cause root rot.

Feeding

From April to September, liquid houseplant feed every two to three weeks at half strength.

Pinching

Pinch or snip out the tips regularly, just above a pair of leaves: it stays compact and branches better.

Humidity

Dry air causes brown edges and spider mite; stand it on a tray of wet gravel or near other plants.

Turning

Turn the pot a quarter turn now and then so it does not lean towards the light.

Renewing

After two or three years it gets bare at the base; replace it with young plants from cuttings.

Tip: Pot three to five rooted cuttings together in one pot: within one season you have a full, rounded plant. Keep a few cuttings in reserve every spring to replace a leggy plant.

Aluminium plant: when to prune it?

Pruning months: March–August.

When: Pinch out the tips regularly throughout the growing season, from March to August. Cut back a leggy, bare plant hard in March or April.

How:

• Pinch or snip out the tips of young shoots just above a pair of leaves; two new shoots form below.
• In March–April, cut long, bare stems back to a few pairs of leaves above the compost.
• Remove yellow and fallen leaves so no mould develops on the compost.
• Use the tips you cut off as cuttings.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Tip cuttings

From March to August: take tips of 8–10 cm with a few pairs of leaves, remove the lower leaves and stand them in a glass of water or in moist cutting compost. They root within a few weeks; then pot three to five together.

Aluminium plant: how does it get through the winter?

• A houseplant that stays indoors all year: below 12 °C it drops leaves and may rot.
• In winter, give it a bright spot closer to the window, but not against the cold glass.
• Water less: let the compost dry out a little more, and do not feed from October to March.
• Keep it away from the dry air above radiators.

Diseases and pests

• Long, bare stems: Too little light or an old plant. Move it somewhere brighter, pinch it more often and replace old plants with cuttings.
• Leaf drop: Cold, draughts, cold wet roots or, on the contrary, a dried-out root ball. Find it a warm spot and water more evenly.
• Root rot: Limp stems turning black at the base, in wet compost. Take healthy tips as cuttings and start again.
• Spider mite: Fine yellow speckles and webbing, especially in dry air. Rinse under the shower and raise the humidity.
• Mealybug: White fluff in the leaf axils. Wipe off with a damp cloth or cotton bud.

Through the year

• January: Rest. Bright spot, little water, no feed.
• February: Rest. Keep away from heating. Watch for spider mite.
• March: Repot. Cut back bare plants. Start feeding.
• April: Root tip cuttings. Feed every two to three weeks.
• May: Growth. Pinch out the tips regularly.
• June: Take cuttings. Keep out of fierce sun.
• July: Growth. Pinch out tips. Raise humidity in hot weather.
• August: Take the last cuttings. Feed.
• September: Last feed. Move closer to the light as the days shorten.
• October: Water less. Stop feeding.
• November: Rest. Away from draughts and cold windows.
• December: Rest. Little water.

Did you know?

• The silver patches are not a pigment: they are thin layers of air under the leaf’s skin that reflect the light.
• It belongs to the nettle family, but has no stinging hairs.
• The well-known Chinese money plant (Pilea peperomioides) belongs to the same genus.