PL. —Phyllanthus niruriBotanical illustration — drop image
Phyllanthus niruri

Chanca Piedra

SpringSummerFall
10a12bHardiness zone
Background

Chanca piedra is a small tropical annual or short-lived perennial in the family Phyllanthaceae, native to coastal lowlands and disturbed ground across South and Central America, India, and Southeast Asia. Its common name translates as 'stone breaker' in Spanish, reflecting its primary ethnobotanical role. Plants reach 12–24 inches tall with fine alternate leaves and inconspicuous flowers arranged along the undersides of slender stems.

In zones 10–12 it self-seeds prolifically and behaves as a persistent volunteer in warm, frost-free gardens. It tolerates part shade and adapts to a range of well-drained soils, performing best in loose, loamy ground at a slightly acidic to neutral pH. Mulching helps retain moisture during dry seasons and suppresses competing weeds around the plant's shallow roots. In cooler zones it must be started indoors and grown as a warm-season annual.

Chanca piedra is documented in Ayurvedic, South American, and South Asian traditional medicine systems for urinary tract conditions and liver support. Laboratory and limited clinical research has identified the compounds phyllanthin and hypophyllanthin with hepatoprotective and antilithic activity. Some human trials have examined its effects on calcium oxalate kidney stone passage and on hepatitis B surface antigen levels.

Care guide
SunFull sun to part shade
WaterModerate; keep evenly moist
SoilMoist, well-drained, humus-rich
Spacing8–12 inches
Height12–24 inches
Zone10a – 12b
Direct sow
Seasonal tasks
spring
watchMonitor seedlings for damping-off; water at soil level, ensure good drainage, and maintain air circulation around young plants.
sowStart seeds indoors 6–8 weeks before last frost if growing outside zone 10; press seeds onto the surface of moist seed-starting mix — they need light to germinate and should not be buried.
sowTransplant or direct-sow outdoors once soil temperature stays above 65°F and all frost risk has passed.
summer
cutHarvest aerial parts — stems and leaves — once plants reach 8–10 inches tall; cut in the morning after dew dries for best potency if using medicinally.
watchCheck soil drainage during heavy rains; standing water around roots promotes rot in this shallow-rooted species.
fall
cutAllow a few plants to set and drop seed before clearing beds; self-sowing is reliable in frost-free gardens and produces volunteers the following season.
Common problems

Damping Off

Symptoms

Seedlings collapse at the soil line with thin, water-soaked stems; seeds may fail to emerge or rot before sprouting.

Treatment

Sow in well-draining mix, avoid overwatering, and ensure good airflow. Remove affected seedlings and let the surface dry between waterings.

Root rot

Symptoms

Plants wilt, yellow, and stunt even in moist soil; lower stems and roots turn brown, soft, and mushy and the plant may collapse. Most common in heavy, wet, or poorly drained ground.

Treatment

Improve drainage and stop overwatering, and never plant too deep. Lift and destroy badly affected plants along with the soil around the roots. Grow in raised or free-draining beds to prevent it returning.

Fungal leaf spot

Symptoms

Brown or purplish spots on the leaves, often ringed with a yellow halo, that spread and merge in warm, humid, or wet weather; heavily spotted leaves yellow and drop early.

Treatment

Pick off spotted leaves and clear fallen debris to remove overwintering spores. Improve air circulation by thinning, and water at the base so foliage dries quickly. If it persists, apply a copper- or sulfur-based fungicide at the first sign.

From the field journal