Watering schedule

How often to water Lemongrass (Cymbopogon citratus) — the schedule

Also called West Indian lemongrass, sereh, fever grass.

About Lemongrass

Cymbopogon citratus · also called West Indian lemongrass, sereh · herb

Lemongrass is a tropical clumping grass from south Asia with intensely lemon-scented stems and leaves used in Thai and Vietnamese cooking. Tender; grown as an annual or overwintered as a houseplant in cool climates. Toxic to pets due to essential oils.

Lemongrass (Cymbopogon citratus, Poaceae) is a frost-tender clumping tropical grass widely grown in the tropics and subtropics for its lemony stalks used in Southeast Asian cooking; hardy only to about USDA zones 9-10.

Requires a great deal of water — water regularly if rainfall is sparse, since this tropical grass does not tolerate drought.

Ideal humidity: 50-70% (outdoor)

Watch for — Browning leaf tips: Tap-water sensitivity or low humidity.

Sources: hort.extension.wisc.edu, plants.ces.ncsu.edu, missouribotanicalgarden.org

The watering schedule, season by season

Lemongrass is a soft, fast-growing herb that wilts the moment it dries out — it wants consistently moist (never soggy) soil and bounces back if you catch it early. The base rhythm for lemongrass is twice-weekly watering, but the real interval moves with the season, the light and the pot — so treat the figures below as a starting point and always confirm with the plant itself.

Spring & summer (active growth): Spring and summer: keep evenly moist, watering as soon as the surface starts to dry — often every 1-2 days for pots in warm weather.
Autumn (slowing down): Autumn: still keep moist but check rather than pour daily as growth slows.
Winter (rest / dormancy): Winter: indoor pots need less; let the top centimetre dry first but never let it wilt hard.

Consistent moisture; lemongrass is a swamp plant in habitat.

Want this turned into a live reminder that adjusts to your home and the weather? The Growli watering calculator takes your pot size, light and season and returns a starting interval for lemongrass in seconds.

How to tell lemongrass needs water

A calendar is the worst way to water lemongrass. Check the plant and the soil instead — for this species, look for these signals in order:

The soil surface is dry to the touch.
Leaves and stems begin to droop or look limp (act now — it recovers if caught early).
The pot is light when lifted.

The most reliable single check is the first one on that list. When two signals agree, water; when they disagree, wait a day and look again — under-watering lemongrass for a day is almost always safer than over-watering it.

Overwatering vs underwatering lemongrass

The two failure modes can look alike at a glance, so check the soil weight and wetness before you decide. For lemongrass specifically:

Signs you are overwatering

Yellowing lower leaves, mushy stems, and a constantly wet pot.
Damping-off or rot at the base of seedlings.
Fungus gnats in permanently wet soil.

Signs you are underwatering

Dramatic wilting and flopping; leaves crisp at the edges if left too long.
Bitter flavour and premature flowering (bolting) after drought stress.

Letting lemongrass dry to a hard wilt repeatedly shortens its life and turns the leaves bitter or triggers bolting — but sitting it in water rots the roots just as fast. Aim for steady, light moisture.

Water quality notes

Tap water is fine for lemongrass; frequency and consistency matter, not water type.

Seasonal and environmental adjusters

Every figure above shifts with the conditions in your home. For lemongrass, the levers that matter most are:

Containers and sunny windowsills dry fast — check daily in summer.
Harvesting regularly keeps the plant compact and lowers its water demand.
A slightly larger pot dries more slowly and is more forgiving than a tiny supermarket pot.

Pot choice is part of this too — work out the right size with the pot size calculator, since a pot that is too big stays wet long enough to rot the roots of lemongrass.

Lemongrass watering — frequently asked questions

How often should I water lemongrass?

Water lemongrass twice-weekly watering. Spring and summer: keep evenly moist, watering as soon as the surface starts to dry — often every 1-2 days for pots in warm weather. Winter: indoor pots need less; let the top centimetre dry first but never let it wilt hard.

How do I know when lemongrass needs water?

The soil surface is dry to the touch. Leaves and stems begin to droop or look limp (act now — it recovers if caught early). The pot is light when lifted. The single most reliable test for lemongrass is the first signal on that list — checking the soil or the plant directly always beats watering by the calendar.

What does an overwatered lemongrass look like?

Yellowing lower leaves, mushy stems, and a constantly wet pot. Damping-off or rot at the base of seedlings. Fungus gnats in permanently wet soil. Letting lemongrass dry to a hard wilt repeatedly shortens its life and turns the leaves bitter or triggers bolting — but sitting it in water rots the roots just as fast. Aim for steady, light moisture.

What are the signs of an underwatered lemongrass?

Dramatic wilting and flopping; leaves crisp at the edges if left too long. Bitter flavour and premature flowering (bolting) after drought stress.

Can I use tap water on lemongrass?