Lemongrass (sereh) care

Light

Lemongrass is a sun-lover and needs the brightest spot in the home to thrive. 6+ hours of direct sun. Indoors that almost always means a south or west-facing windowsill in the northern hemisphere. Plants moved abruptly from low light to direct sun will scorch — acclimate them over 7-10 days by giving a little more sun each day.

Watering

Water lemongrass twice-weekly watering. The actual day count varies with pot size, light level, and the season — the finger test (or, better, lifting the pot to feel its weight) is more reliable than a calendar. Empty any drainage saucer after watering so the pot is never sitting in water. Consistent moisture; lemongrass is a swamp plant in habitat.

Soil and pot

Lemongrass grows best in rich free-draining loam. Compost-rich; pH 6.0-7.5. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Lemongrass sits happiest at around 50-70% (outdoor) humidity and 21-29°C (70-85°F). Loves humidity. If you keep the room above 21 year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed lemongrass sparingly. Balanced feed monthly during growth. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on lemongrass in the Growli community. Each is annotated with the most common cause so you know where to start.

• Slow start — Needs heat; wait until soil is above 18°C.
• Frost damage — Tender — bring indoors or dig clump in autumn.
• Browning leaf tips — Tap-water sensitivity or low humidity.
• Pot-bound in containers — Divide and pot up annually.
• Spider mites indoors — Rinse foliage and raise humidity.

Companion plants

Lemongrass pairs well with Basil, Cilantro, and Mint. These are species with similar light and water needs, so you can grow them in the same bed or container without conflict.

Propagation

Divide established clumps in spring; rooting fresh stalks in water also works. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Lemongrass is toxic to pets. ASPCA lists Cymbopogon citratus as toxic to cats and dogs due to essential oils (citral and geraniol). Large amounts cause vomiting and depression; small culinary uses are tolerated. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Lemongrass deep-dive guides

Every aspect of lemongrass care, each with its own calibrated guide:

• Lemongrass watering schedule
• Lemongrass light requirements
• Best soil mix for lemongrass
• Lemongrass fertilizing guide
• When to repot lemongrass
• How to propagate lemongrass
• Lemongrass growth rate & size
• Lemongrass cold hardiness
• Lemongrass temperature & humidity
• Is lemongrass toxic to cats & dogs?

Related guides

Lemongrass is also known as West Indian lemongrass, sereh, and fever grass.

• Basil care — light, water and common problems
• Herb garden care — light, water and common problems
• Mint care — light, water and common problems
• All 200 plant care guides in the Growli library