Lemongrass
Cymbopogon citratus
Also known asWest Indian lemongrass · Sereh · Tanglad · Takhrai · Limonaria
Environment
The bounded range this crop tolerates. Strict on light; outside the DLI band, yields drop sharply.
Climate and zones
- USDA zones
- 10–13 (winter low around -1°C)
- Frost
- frost sensitive (dies at first frost)
- Season
- year-round tropical
Growing systems
Root mass: heavy. Thin-channel systems can't hold this crop.
Growing media
| Medium | pH effect | Retention | Bacterial surface |
|---|---|---|---|
| Expanded clay pebbles (LECA) | neutral / inert | low | high |
| Coco coir (Coconut coir) | slightly acidic | high | moderate |
| 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 | 2 |
Companion-growing notes
- High transpiration. Regular reservoir top-ups needed during fruiting.
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
One of the easiest tropical crops for container or hydroponic growing. Large container (10 L) or media bed. EC 1.5-2.5 mS/cm. pH 5.5-7.0. Temperature: 20–35°C (tropical; growth stops below 15°C, frost kills the plant). High light (DLI 16-25 mol/m2/day; supplemental lighting extends production in northern climates). Propagation is simple: buy fresh lemongrass stalks from a grocery store (with the base intact), place them in water until roots develop (7-14 days), then plant. Each rooted stalk develops into a clump of 10-20+ stalks within a season. Harvest individual stalks by pulling and twisting them from the outer edge of the clump. Use the bottom 10–15 cm of each stalk (the tender, pale interior); bruise it by smashing with the flat of a knife before adding to soups and curries. The clump regenerates continuously. Bring containers indoors before first frost; the plant survives winter in a bright window as long as it stays above 10°C. For Southeast Asian cooking, fresh lemongrass is one of the most valuable crops you can grow; a single clump provides year-round supply.