Pilea Moon Valley

How to care for Pilea Moon Valley

Light

Pilea mollis thrives in bright, indirect light and will produce its most vivid leaf colouration when given adequate brightness without direct sun exposure. A position near a north- or east-facing window, or set back from a south- or west-facing window screened by a sheer curtain, is ideal. Prolonged direct sun will scorch and bleach the leaves, whilst very low light causes the plant to become leggy and the textured leaf surface to lose definition.

Watering

Water thoroughly when the top centimetre of compost has dried out, then allow any excess to drain freely. Avoid leaving the plant sitting in a saucer of water, as the roots are sensitive to waterlogging and will rot quickly in saturated conditions. Reduce watering frequency in winter when growth slows, but never allow the compost to dry out completely. Use room-temperature water, and if possible use rainwater or filtered water to avoid mineral build-up on the foliage.

Soil and potting

A light, well-draining compost is essential. A peat-free multipurpose compost blended with around 20 to 30 per cent perlite or coarse horticultural grit provides the right balance of moisture retention and aeration. Avoid heavy, dense mixes, as these stay wet for too long and encourage root rot. A slightly acidic to neutral pH of around 6.0 to 7.0 is appropriate.

Feeding

Feed with a balanced, diluted liquid fertiliser at half the recommended strength every two to four weeks during the spring and summer growing season. A fertiliser with an NPK ratio of roughly equal parts, such as a 10-10-10 formula, suits this foliage plant well. Discontinue feeding from late autumn through winter when the plant is not actively growing, as excess nutrients at this time can cause salt build-up in the compost.

Humidity and temperature

Pilea mollis originates from humid tropical environments and benefits significantly from higher ambient humidity, ideally above 50 per cent. Misting the leaves, placing the pot on a tray of damp pebbles, or using a room humidifier will all help maintain adequate moisture in the air. The plant prefers temperatures between 15 and 26 C and should not be exposed to cold draughts, sudden temperature drops, or temperatures below about 10 C, which can cause leaf damage and decline.

Repotting

Repot in spring when roots begin to emerge from the drainage holes or the plant shows signs of becoming root-bound, typically every one to two years. Move up only one pot size, as an oversized pot retains too much moisture and increases the risk of root rot. A pot with good drainage holes is essential. After repotting, water in well and keep the plant out of direct sun for a week or two to allow it to settle.

Pruning

Pilea mollis tends to become straggly and loses its compact habit relatively quickly, so regular pinching out of the growing tips is recommended to encourage bushy growth. Pinch or cut back the stem tips just above a leaf node to stimulate branching. Any yellowing, damaged, or dead leaves and stems should be removed promptly with clean, sharp scissors or secateurs. The plant is generally short-lived as a houseplant, often declining after two to three years, at which point propagating fresh plants is the best course of action.

Is Pilea Moon Valley toxic?

Common problems

How to propagate

Stem tip cuttings

Cut a healthy stem tip 5 to 8 cm long just below a leaf node, remove the lower leaves, and place in a small pot of moist perlite or propagating compost. Keep in a warm, humid spot with bright indirect light and roots should form within two to four weeks.

Division

When repotting a mature clump, the plant can be carefully separated into two or more sections, each with healthy roots and stems attached. Pot each division individually and keep in warm, humid conditions until established.

Where Pilea Moon Valley comes from

Native to Colombia, Venezuela, Costa Rica, Central America.

Story and origins

The genus name Pilea derives from the Latin word 'pileus', meaning a felt cap or hat, which refers to the shape of one of the tepals in the small flowers of plants in this genus, which resembles a cap covering the achene. The species epithet mollis is Latin for 'soft' or 'tender', a reference to the soft texture of the leaf surface. The popular trade name 'Moon Valley' was coined to reflect the plant's dramatically textured leaf surface, which was said to resemble the cratered landscape of the moon.

Pilea mollis is native to tropical regions of Central and South America, where it grows as a ground-level plant in humid forest understoreys. The species was formally described in the botanical literature in the twentieth century. It entered widespread commercial cultivation as a houseplant during the latter half of the twentieth century, largely under the trade name 'Moon Valley', which helped cement its popularity particularly in Europe and North America. Its unusual foliage texture distinguished it from many other small-leaved houseplants available at the time, and it became a staple of mixed tropical houseplant collections. Unlike the more culturally prominent Pilea peperomioides, which has a well-documented history of being passed between plant enthusiasts, Pilea mollis has remained primarily a commercially propagated plant sold through nurseries and garden centres.

Varieties to know

Pilea mollis 'Moon Valley'

The trade name under which the species is almost exclusively sold; characterised by deeply bullate, lime-green to chartreuse leaves with dark brown midribs and veins.

Fun facts

• The deeply textured surface of the leaves, which gives rise to the 'Moon Valley' trade name, is formed by the raised network of veins and sunken leaf tissue between them, a surface structure known as bullation.
• Pilea mollis is a member of the nettle family, Urticaceae, yet unlike many of its relatives it lacks the stinging hairs found in true nettles.
• The genus Pilea is one of the largest genera in the family Urticaceae, encompassing approximately 600 to 700 species distributed across tropical and subtropical regions worldwide.
• Small, inconspicuous pinkish flowers can appear on Pilea mollis when the plant is grown in optimal conditions, though they are rarely the reason people grow it.
• Pilea species are known to be explosive pollen releasers, with anthers that can discharge pollen in a tiny, rapid burst when triggered, a mechanism for wind pollination.

Pilea Moon Valley FAQ