Pilea as a Houseplant

Pileas have gained popularity in the past decade as houseplants, particularly the Chinese money plant (Pilea peperomioides). The Pilea genus is the largest of the nettle family (Urticaceae), with 600–715 species. Luckily, it does not contain stinging hairs like its well-known family member, stinging nettle (Urtica dioica). Pilea species are found throughout tropical and subtropical regions, except Australia and New Zealand. Since most of the species are found on the shady forest floor, are low-growing, and have unique foliage, they make ideal plants for the home.

Flowers are small and hardly bloom indoors. However, the genus Pilea originates from the Latin pileus, meaning "cap," which is a reference to the shape of the flowers. The foliage varies from species to species. Here are some notable Pilea species that are ideal for the home environment:

Aluminum plant, or watermelon plant (Pilea cadierei) gets its common names from the stripes of silvery white (appearing like aluminum) on the elliptic (watermelon-shaped) foliage. The clumping, compact pilea is native to the tropical forests of China and Vietnam. It grows 6–12 inches tall and 6–9 inches wide.

Friendship plant (Pilea involucrata) is named as such because it is so easy to propagate and share with friends. The species has green-bronze, ovate, and toothed foliage with a crinkly texture, typically with light green margins and dark red undersides. It is native to the understory of tropical forests in Central and South America. The specific epithet 'involucrata' means that it has a ring or whorl of bracts at the base of the flower. The flowers are tiny, with a pinkish hue, and held on a cyme inflorescence (branched clusters in which each flower is held on an individual stalk), but typically will not bloom when grown as a houseplant.

Moon Valley plant (Pilea mollis 'Moon Valley')* is native to Central and South America. The foliage of this pilea is puckered or "cratered," if you will, creating valleys. The textured and toothed ovate leaves are bronze-green with brighter green margins, similar to friendship plant, but with sunken purple veins. 'Moon Valley' is a 12-inch-tall mounding cultivar with light blooms in cymes.

Creeping Pilea (Pilea nummulariifolia) is known as a weed when grown outdoors, but when placed in a hanging container, it makes for a lovely houseplant. The trailing plant is native to Central America and the Caribbean, south to Peru and Venezuela. The shiny, medium green leaves are ovate with scalloped margins.

Chinese money plant (Pilea peperomioides) has been a star indoor plant since the onset of the houseplant boom in the 2010s. The plant originates from the cool, shady mountains of the Yunnan Province in southern China. Its unique, fleshy, coin-shaped foliage lent it the common name of "money" plant. The money plant has a compact habit, 8–12 inches tall and wide.

*Note that there is some confusion related to 'Moon Valley' and whether it is P. mollis or P. involucrata. This occurs in both botanical gardens and retail spaces. The author found both plant labels at Phipps Conservatory and Botanical Gardens. The best explanation related to this cultivar is from the Missouri Botanical Garden: "'Moon Valley' is also commonly sold in commerce as a cultivar of Pilea involucrata, but synonymity has not been conclusively determined."

Cultural Requirements

Temperature and Humidity

A warm, humid environment is ideal for Pilea species making a home indoors. Some species require high humidity, especially during colder months. The article, Humidity and Houseplants, can provide insight into a method that will work best for your home. Standard indoor plant temperatures work for most pileas, with daytime temperatures between 65–75^oF  and night temperatures higher than 55^oF. Avoid putting plants near drafts or vents.

Light

It is important to remember that pileas are low-growing tropical and subtropical species. They should not be exposed to direct light. A bright, indirect light source is the best. The plant can be placed several feet away from a window, or the light can be filtered through a sheer curtain or blinds.

Water and Fertilizer

Pilea houseplant species like watering to be just right. No overwatering or underwatering.

Soil and Repotting

A well-drained potting mix, such as a specified houseplant potting mix, will work for most species. Those species that prefer well-drained soils, add an equal part of cacti potting mix. When potting and repotting pileas, consider the root ball versus the foliage. Choose a pot that is roughly 2 inches bigger in diameter than the roots.

Pests and Diseases

Monitor for typical houseplant pests, such as aphids, mealybugs, spider mites, scale, and fungus gnats. Ensure that watering is ideal for the plant to prevent root rot. Bacterial leaf spot can occur with overly high humidity. Look for brown to black spots on leaves that become mushy. Prompt removal and disposal of leaves, with a decrease in humidity and an increase in air circulation, is the best way to prevent a recurrence of the leaf spot. Some species tend to get leggy, have elongated stems with fewer leaves, with inadequate light.

Propagation

Since Pilea houseplants are foliage-based, stem or leaf cuttings are an easy way to propagate plants during the growing season. Pilea peperomioides also produces offsets, also called pups, which can be removed and potted separately from the parent plant.