Lemongrass Cymbopogon citratus
Reviewed June 2026 · how we check this
A tall, clumping tropical grass grown for its fragrant, citrus-scented stalks — the bright lemony base of Thai and Vietnamese cooking. Fast and vigorous in heat and full sun, it fills a pot or border with arching blades in a single season and rewards generous watering.
Light
Lemongrass is a sun-worshipper — give it the brightest, hottest spot you have, with at least 6 hours of direct sun a day and 8 or more for the lushest, most fragrant growth. Full sun drives the vigorous flush of new stalks that make this grass worth growing. In too little light it grows thin, floppy, and pale, with weak stems that lack the strong citrus oils prized in the kitchen. Indoors it needs a south-facing window or a grow light directly overhead; a shady patio corner will leave it sparse and sulking all season.Watering
This is a thirsty tropical grass that wants consistently moist soil — never bone-dry, never waterlogged. In peak summer heat a potted plant may need watering daily, while garden clumps appreciate a deep soak two or three times a week. Lemongrass naturally grows along streambanks, so it tolerates plenty of moisture as long as the soil drains and roots aren't standing in stagnant water. Let the surface barely begin to dry between waterings, then water thoroughly. Curling, browning blade tips usually mean it ran too dry; ease off only in winter when growth stalls.Soil & potting
Plant lemongrass in rich, fertile, well-draining soil with plenty of organic matter to fuel its fast growth and hold steady moisture. A loamy garden bed amended with compost is ideal; in containers use a quality potting mix enriched with compost, and pick a generous pot — clumps expand quickly and a crowded plant needs dividing within a year or two. Always choose a container with drainage holes so excess water escapes. A slightly acidic to neutral pH around 6.0–7.0 suits it well, and a mulch layer outdoors keeps the roots cool and damp.Humidity & temperature
As a tropical native, lemongrass loves warmth and humidity — it thrives between 65 and 95°F and grows fastest in the steamy heat of midsummer. It is frost-tender: temperatures below about 40°F stall it, and a hard freeze kills the top growth, though established roots may resurface in zones 8–9. In dry climates it appreciates extra humidity, so group pots or mist on hot afternoons. Where winters are cold, grow it in a pot and move it indoors to a warm, bright window before the first frost, or treat it as an annual.Fertilizing
Lemongrass is a hungry grass that responds to steady feeding with a flush of new stalks. During the spring and summer growing season, feed every 2–4 weeks with a balanced liquid fertilizer, or favor a nitrogen-rich formula to push the leafy blade growth you're harvesting. A topdressing of compost at planting and again midseason works well in the garden. Ease off feeding in fall as growth slows and stop entirely in winter. Pale, sluggish plants in summer are often simply underfed — a dose of liquid fertilizer greens them up fast.Pruning & maintenance
Harvest by grasping an outer stalk near the base and twisting or cutting it off at soil level — take the thick, pale lower stem for cooking and the fragrant blades for tea. Harvest the oldest outer stalks first and the clump keeps producing all season. Trim ragged or browned blade tips anytime to keep it tidy, and cut the whole clump back to a few inches in late fall in mild climates to renew it. Wear gloves: the blade edges are fine-toothed and can give you a paper-cut-like nick.Propagation
Easiest from division or rooted stalks rather than seed, but you can start it from seed too. Sow seed indoors 6–8 weeks before your last frost, pressing it lightly onto the surface of moist seed-starting mix and keeping it warm at 70°F or above — bottom heat speeds germination, which takes 1–3 weeks. Keep the tray bright and evenly moist, then pot up seedlings once they have a few blades. Even simpler: stand a fresh grocery stalk in water until roots appear in a couple of weeks, then plant it.Common problems
Through the year
Spring
Plant out or divide after the last frost once nights stay warm — start feeding and water steadily as new stalks emerge.
Summer
Peak growth in the heat. Water generously, feed every couple of weeks, and harvest outer stalks freely.
Fall
Growth slows with cooler nights. Take a final harvest, ease off feeding, and pot up or move the plant indoors before frost.
Winter
Near-dormant. Keep an indoor pot warm and bright, water sparingly, skip fertilizer, and protect roots from freezing.
Companion planting
Lemongrass pairs well with tomatoes, peppers, and other sun-loving crops, and its citronella-scented oils help deter mosquitoes and some pests near patios and seating areas. Keep it at the edge of a bed, though — a vigorous clump can crowd smaller herbs.
Recommended supplies for Lemongrass
- A seed-starting kit
- A balanced liquid fertilizer
- A seedling heat mat
- Pots with drainage holes
- Frost cloth for cold snaps
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