Fish mint
Also known as
Chameleon plant, Fish herb, Fishwort, Lizard tail, Heartleaf, Dokudami, Yu xing cao, Eoseongcho, Rau diếp cá
Keep this plant’s care guide close at hand.
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Houttuynia cordata is a rhizomatous, cold-hardy perennial native to East and Southeast Asia. It forms dense mats of heart-shaped leaves, 3–8 cm wide, that release a distinctive fishy aroma when bruised. In late spring to summer it produces small, yellowish flower spikes surrounded by four showy white bracts. Plants typically reach 20–60 cm tall and spread rapidly via creeping underground rhizomes. The popular variegated cultivar ‘Chameleon’ displays splashes of green, cream, and red. Houttuynia thrives in consistently moist to wet soils along streams, pond margins, and damp woodland edges, and it is often used as a marginal aquatic or groundcover in shade gardens. The foliage and roots are edible and used as an herb in Vietnamese, Chinese, and Japanese cuisines and traditional medicine. Because it spreads aggressively and can become invasive where hardy, it is best confined to containers or beds with barriers, especially near natural areas. Aboveground growth dies back in winter and re-sprouts vigorously in spring.
Taxonomy
Properties & Requirements
How to care for Fish mint
Water
Keep the root zone constantly moist; never allow the soil to dry out. Water container plants whenever the top centimeter feels damp rather than dry—often daily in hot weather. Houttuynia tolerates soggy conditions and can grow with its crown just above water in 2–5 cm of standing water, making it ideal for pond margins. Ensure containers don’t run out of water and use saucers or cachepots to maintain humidity. Reduce watering in winter dormancy but don’t let rhizomes desiccate.
Light
Prefers partial shade to full shade, especially in warm climates. Morning sun with afternoon shade produces compact, lush growth; full sun is tolerated in cool regions if the soil stays consistently wet. In hot, arid sites, excessive sun causes leaf scorch and stunting. Variegated forms color best with bright, indirect light. Indoors, place near an east or north window or provide bright filtered light; avoid prolonged, intense midday sun unless plants are growing in saturated soil.
Nutrients
An undemanding feeder, fish mint responds best to organic-rich soil rather than heavy fertilization. In containers or confined beds, mix compost into the substrate and apply a balanced, slow-release fertilizer (e.g., 5-5-5 or 10-10-10) at label rates in early spring. During active growth, a half-strength liquid feed monthly is sufficient; for pond culture, use aquatic plant tabs pushed into the medium every 6–8 weeks. Avoid overfertilizing, which promotes rampant spread and weak, floppy growth.
Temperature
Hardy outdoors in USDA Zones 4–10, houttuynia dies back in freezing weather and re-sprouts in spring. Ideal growth occurs between 10–25°C (50–77°F), but established clumps tolerate summer heat if kept wet and shaded. Roots can survive to roughly −30°C (−22°F) under mulch. In hot climates, provide midday shade and abundant water to prevent leaf scorch. Indoors or in mild winters, keep above 5°C (41°F) to maintain foliage, though seasonal dormancy improves vigor.
