Vietnamese Coriander

Persicaria odorata is native to Southeast Asia.

• Found throughout Vietnam, Cambodia, Laos, Thailand, Malaysia, and Indonesia
• Grows naturally in moist, marshy areas, along stream banks, and in wet meadows
• Often found as a volunteer plant in rice paddy margins
• Cultivated in home gardens throughout Southeast Asia for millennia
• Sometimes classified as Polygonum odoratum in older literature
• First described scientifically in the 19th century
• Now cultivated in tropical and subtropical gardens worldwide
• Also grown hydroponically for the restaurant industry
• An essential component of Southeast Asian herb gardens

A creeping, perennial herb forming dense mats 15 to 30 cm tall.

Stems:
• Prostrate to ascending, jointed (characteristic of Polygonaceae)
• Green to reddish, rooting at the nodes
• Slender, hollow between nodes

Leaves:
• Lanceolate to narrowly elliptic, 5 to 12 cm long and 1.5 to 3 cm wide
• Dark green above, often with a distinctive dark reddish-purple V-shaped marking or blotch near the center
• margins entire, slightly undulate
• Alternate arrangement at each swollen node
• Petioles very short; leaves nearly sessile
• Ochrea (stipular sheath) present at each node

Flowers:
• Small, pink to white, 3 to 4 mm
• Born in terminal spikes 2 to 5 cm long
• Inconspicuous and rarely produced in cultivation

Fruit:
• Small, dark brown to black, three-sided achene
• Rarely produced outside of native habitat

Persicaria odorata occupies a specific ecological niche in Southeast Asian wetland and riparian habitats.

Habitat:
• Native to Southeast Asia — found throughout Vietnam, Cambodia, Laos, Thailand, Malaysia, and Indonesia
• Grows naturally in moist, marshy areas, along stream banks, in wet meadows, and at the margins of rice paddies
• Found at elevations from sea level to approximately 500 meters in warm, humid tropical lowlands
• Requires consistently moist to wet soil — does not tolerate drought
• Thrives in full sun to partial shade in humid tropical conditions
• USDA zones 9–12 (tropical perennial, frost-sensitive)

Growth Habit:
• Creeping, mat-forming perennial herb, 15 to 30 cm tall, spreading indefinitely by rooting at nodes
• Semi-aquatic — can grow with roots submerged in shallow water
• Evergreen in frost-free tropical conditions; dies back in cool weather
• Extremely vigorous in warm, wet conditions — can spread several meters per season

Pollination:
• Small, pinkish-white flowers are produced on terminal spikes but are relatively inconspicuous
• Primarily self-pollinating; insect pollination is minimal
• Seed production is limited — reproduction is predominantly vegetative through stem fragmentation and rooting at nodes
• Flowering occurs sporadically throughout the year in tropical conditions

Ecological Role:
• Forms dense mats along waterways that stabilize stream banks and reduce erosion
• Provides cover and foraging habitat for aquatic and semi-aquatic invertebrates, frogs, and small fish
• Aromatic essential oils in the leaves deter most herbivorous insects
• Leaves are occasionally browsed by waterfowl and semi-aquatic mammals
• Common volunteer plant in traditional Southeast Asian rice paddy ecosystems

Invasive Status:
• Can spread aggressively in warm, wet conditions but is not classified as invasive
• Easily controlled by cutting or drying out the growing area
• Widely cultivated in homegardens and does not escape into natural ecosystems

Vietnamese coriander leaves contain beneficial compounds.

• Per 100 g fresh leaves: approximately 25 to 35 kcal
• Contains vitamins A, C, and small amounts of B vitamins
• Provides iron, calcium, and potassium
• Rich in essential oils including aldehydes and terpenes responsible for the characteristic flavor
• Contains antioxidant polyphenols and flavonoids
• The essential oil includes decanal, dodecanal, and other aldehyde compounds
• Low in calories and fat
• Used in quantities too small to be a major nutritional source

Propagated by stem cuttings; rarely grown from seed.

• Take 10 to 15 cm stem cuttings with at least 2 to 3 nodes
• Remove lower leaves and plant in moist soil or root in water
• Rooting occurs in 5 to 10 days
• Plant in rich, consistently moist to wet soil
• Space plants 20 to 30 cm apart
• Can be grown in containers, hydroponically, or in boggy ground
• Requires partial shade to full sun; prefers filtered light in hot climates
• Never allow soil to dry out — this is a water-loving plant
• Fertilize monthly with balanced liquid fertilizer
• Harvest leaves regularly to promote bushy growth
• Perennial in frost-free climates; grows year-round in the tropics
• In temperate climates, grow as an annual or bring indoors for winter

Culinary uses:
• Essential in Vietnamese cuisine: served with pho, added to spring rolls, used in banh mi sandwiches
• In Malaysia and Singapore, a mandatory herb in laksa (spicy noodle soup)
• In Cambodia, used in numerous fresh salads and soups
• Added to Thai salads (som tam, yam) for its citrusy-coriander flavor
• Used as a garnish and wrapping leaf for grilled meats
• The leaves are typically added raw at the last minute or served as a side garnish
• Cooking diminishes the flavor, so it is usually used fresh
• In Laos, used in laap (minced meat salad)
• Can be used anywhere a bold, fresh coriander-mint flavor is desired