Vietnamese coriander
Persicaria odorata
Also known asRau ram · Vietnamese mint · Cambodian mint
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 9–13 (winter low around -7°C)
- Frost
- frost sensitive (dies at first frost)
- Season
- year-round tropical
Growing systems
Root mass: moderate.
Growing media
| Medium | pH effect | Retention | Bacterial surface |
|---|---|---|---|
| Rockwool (Mineral wool) | alkaline until pre-soaked | very high | low |
| Expanded clay pebbles (LECA) | neutral / inert | low | high |
| Coco coir (Coconut coir) | slightly acidic | high | moderate |
| Net pot, no medium (Bare-root) | - | - | - |
| Soil-based mix (Potting soil) | varies | high | high |
Nutrient demand by stage
NPK ratios are relative weights. EC targets shift through the plant's life.
| Stage | N | P | K | EC (mS/cm) |
|---|---|---|---|---|
| seedling | 1 | 1 | 1 | 0.8 |
| vegetative | 3 | 1 | 2 | 1.5 |
Aquaponics suitability
Compatible
Fish waste provides enough nitrogen for healthy growth. Supplemental potassium, calcium, and iron may still be needed depending on fish stocking density.
Care notes
An easy, productive herb for warm, moist hydroponic systems. EC 1.0-2.0 mS/cm. pH 5.5-7.0. Temperature: 20–32°C (tropical; frost-sensitive). Moderate to high light (DLI 12-20 mol/m2/day; tolerates partial shade). The semi-aquatic nature makes it ideal for NFT, DWC, and raft systems where roots are constantly in contact with water. Propagation by stem cuttings: every node roots rapidly in water. From cutting to harvestable plant: 3-4 weeks. Harvest by cutting stem tips; the plant branches and grows vigorously in warm, moist conditions. The flavor is at its peak in warm weather (the opposite of cilantro, which is at its worst in heat), making Vietnamese coriander the perfect warm-season cilantro substitute. For pho garnish, spring rolls, and laksa, fresh rau ram is traditional and irreplaceable. A few plants in a hydroponic system provide year-round supply in warm conditions.