Culture
Winter hardy to USDA Zone 11-12. In St. Louis, grow indoors in a warm, humid environment in bright indirect light. Some morning sun is acceptable, but avoid full afternoon sun. Use a peaty soil-based potting mix. Plants like high humidity, and appreciate humidified rooms or placement on a bed of wet pebbles. Water moderately in the growing season, and reduce watering in fall to late winter. Pinch stem tips as needed to keep plant compact. Easily propagated from stem cuttings.
Noteworthy Characteristics
Pilea microphylla, commonly called artillery plant, is native from Mexico to Brazil. It is a short-lived perennial or annual that typically grows from 8-12” tall. In its native habitat, it may spread to as much as 24” wide and is sometimes massed as a ground cover. Abundant, tiny, obovate to rounded, succulent, light green leaves (1/4” to 1/2” long) appear on this small shrubby plant, giving it an almost fern-like appearance. Tiny greenish flowers are not particularly showy. Male flowers explosively discharge pollen into the air, hence the common name of artillery plant. Indoor plants rarely flower and fruit.
Genus name comes from the Latin word pileus meaning a cap from the shape of the female flowers.
Specific epithet means small-leaved.
Problems
Watch for mealybugs and spider mites. Leaf spots and stem rot may occur. Stems are fragile and break easily. Has been known to escape cultivation and is considered invasive in a number of tropical and sub-tropical regions around the world. Check with local laws and recommendations before adding this plant to your landscape.
Uses
Outdoor ground cover in the tropics. Small indoor plant. Annual for outdoor containers.