Common name: Aluminum Plant, Watermelon Pilea
Description and habitat: Pilea cadierei is a fast growing evergreen perennial native to tropical Southeast Asian rainforest. It has been naturalized extensively in many tropical location around the world. It spreads rapidly in its tropical native habitat where it grows as a groundcover.
Description: Pilea cadierei are attractive foliage plants upright-growing. After about a year, however, when it has reached a height of 25-30cm (10-12 inch), it may drop its lower leaves, leaving bare basal stems. Leaves are thin, up to 8cm (3 inch) long, oblog-oval and arranged in opposite pairs. Their edges are slightly incised and the surface has four rows of raised silvery patches between the green vein areas. Tiny flowers may appear at any season but are scarcely noticeable.
Houseplant care: Pilea cadierei is an easy maintenance indoor plant as long as its need for humidity is supplied. Keep Pilea cadierei out of cold or hot drafts.
The main shoots of Pilea cadierei naturally divide into side branches and dense growth is usually automatic. But it may be advisable to nip out over-ling shoots sometimes, thus balancing and encouraging further division. Also, pinch off the flowers when appears in summer.
Light: Pilea cadierei do well in semi-shade and can be grown at a short distance from a window in summer. Avoid very bright light – especially direct sunlight – at all times.
Temperature: These tropical plants like a combination of warmth (16-24°C (60-75°F)) and humidity. Pots should be stood on trays of moist pebbles. Pilea cadierei cannot tolerate temperatures below 13oC (55oF).
Watering: Water sparingly making the entire potting mixture barely moist but never allowing the mixture get too wet. Let the top two-thirds of the mixture dry out between waterings. Use tepid water or, if it is possible, rain water to water Pilea cadierei.
Fertilising: Apply standard liquid fertiliser once every two weeks, from mid-spring through summer only.
Potting and repotting: Use either an equal-parts mixture of peat moss and soil-based potting mixture or a peat-based mixture. Pilea cadierei do not have a large root system and will thrive in 8-10cm (3-4 inch) pot or in shallow pans. Because Pilea cadierei deteriorate, they should not be moved on. Restart from cuttings.
Cultivation: When kept outdoors in the garden, the Pilea cadierei grows hardy to zone 10a to 11. It grows in moist, well-drained soil, preferring loamy soil. In tropical environments Pilea cadierei is popular as a smaller scale ground cover for shady spots in humid climates.
Propagation: Propagate Pilea cadierei by cuttings taken in late spring. Cut the stem just below a node – the place where a leaf is attached. Take young tip cuttings up to 8cm (3 inch) long, dip their cut ends in hormone rooting powder and insert each in a 5-8cm (2-3 inch) pot of gritty rooting mixture (one part of coarse sand or perlite to two of peat moss). Each cutting will normally root in about three to four weeks if placed in a warm, shady position and watered enough to keep the mixture barelly moist. When the cutting is well rooted move it into recommended mixture and treat it as a mature plant.
Foliage on Pilea cadierei plant will discolor in the sun.
Treatment: Locate the plant in the full shade to prevent this.
Discoloured leaves with brown tips and edges are caused by overexposure to light or a sudden drop in temperature.
Excessive leaf fall in winter indicate either overwatering or low temperatures.
Mites can spoil the foliage in hot, dry weather.
Treatment: Use a suitable pesticide and follow manufacturer instructions.
Pilea cadierei ‘Minima’ is a dwarf variety very similar with Pilea cadierei, but it has leaves about half as big as those of the original species and it seldom grows to become any more than 15cm (6 inch) in height.
Usage: Window sill and potted plant are the simplest ways of displaying this plant. Pilea cadierei contrast well with the foliage of other plants with which they may be quite effectively grouped together. Also, Pilea cadierei can be used for hanging baskets or cascading down a wall. Pileas are grown mainly for their highly textured and metallic foliage. A collection of several different varieties would make an attractive display on a window with bright but indirect light.
The love of Pilea cadierei for humidity makes this plant suitable for terrariums.
By using this plant as ground cover it will resemble its natural habitat.
Notes: Sometimes, Pilea cadierei is sold in pet shops as aquatic plat. The plant will survive fine underwater for a few months, maybe even a year, but it will steadily decline until it finally die. Since it is not true aquatics, it cannot survive submerged for long periods of time. Expected life span of Pilea cadierei while submerged is about 4 to 6 months.
Lifespan: Cut back each year and it will last for several years. If it gets too leggy, take cuttings and discard the plant.
Foliage – coloured
Shape – bushy
Height: 25-30cm (10-12 inch)
Watering in active growth period – sparingly
Light – medium
Temperature in active growth period – min 13°C max 24°C (55-75°F)
Humidity – high
Hardiness zone: 10a-11