Mature size & growth rate

How big does Lemongrass (Cymbopogon citratus) get?

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.

Clumps grow slowly until summer heat and humidity arrive, then enlarge dramatically into dense clumps up to 6 ft wide; frost kills it, so harvest or dig and overwinter indoors before freezing.

Mature size: 1-1.5 m tall and wide

Watch for — Slow start: Needs heat; wait until soil is above 18°C.

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

Indoor size vs how big it gets in the wild

Lemongrass reaches its full size within one growing season — there is no "long-term" size, just how big it gets before you harvest or it dies back. Indoors and in a pot, expect 1-1.5 m tall and wide. A pot, your light levels and a little pruning are what set the final size in a home, far more than the plant's theoretical potential.

It sizes up fast and once, racing from seedling to full size in a single season; after cropping it is finished, so size is a within-season question.

Growth rate and years to mature

Lemongrass is a moderate grower. Realistically, expect a single growing season — it reaches full size in one year, then is done. Its feeding profile backs this up: balanced feed monthly during growth.

Want this turned into the right next pot at the right moment? The pot size calculator and the lemongrass repotting guide cover when and how much to size up — pot size is one of the biggest levers on how fast lemongrass grows.

How to keep lemongrass smaller

You are not stuck with the maximum size. For lemongrass specifically, these are the levers, in order of impact:

Choose a compact or dwarf variety of lemongrass from the start — that is the most reliable size control for an annual.
Grow it in a smaller container to naturally limit how large it gets.
For some crops, pinching or pruning the growing tips keeps the plant shorter and bushier.
Sow a little later or space plants closer if you specifically want smaller individual plants.

How to grow lemongrass bigger or faster

If you want it to fill the space sooner, push the conditions rather than hoping — for lemongrass the accelerators are:

Full sun, warm soil and steady water are what drive a crop to full size fastest.
Sow at the right time for your zone so it gets the whole season to size up.
Feed appropriately for the crop and never let it check (stall) from drought or cold.

Light is almost always the ceiling. The lemongrass light requirements page covers exactly how bright a spot it needs to grow at its potential instead of stalling.

When lemongrass outgrows the room (or the pot)

"Too big" usually arrives as one of these signs for lemongrass:

It sprawls beyond its bed or container before harvest — usually a spacing or support issue.
It flops or needs staking once it hits full height.
Once it has fruited or bolted, it is at its final size for good — the next plant is a new sowing.

If it is the pot rather than the room, it is a repotting job, not a goodbye — see the lemongrass repotting guide. If you want more of this plant instead of a bigger one, the lemongrass propagation guide turns prunings into new plants.

Lemongrass size — frequently asked questions

How big does lemongrass get?

Lemongrass reaches 1-1.5 m tall and wide when grown indoors. It sizes up fast and once, racing from seedling to full size in a single season; after cropping it is finished, so size is a within-season question.

Is lemongrass slow or fast growing?

Lemongrass is a moderate grower. Expect a single growing season — it reaches full size in one year, then is done. Lemongrass reaches its full size within one growing season — there is no "long-term" size, just how big it gets before you harvest or it dies back.

How long does lemongrass take to reach full size?

Roughly a single growing season — it reaches full size in one year, then is done. Light, pot size and feeding move that timeline more than anything else.

How do I keep lemongrass smaller?

Choose a compact or dwarf variety of lemongrass from the start — that is the most reliable size control for an annual. Grow it in a smaller container to naturally limit how large it gets. For some crops, pinching or pruning the growing tips keeps the plant shorter and bushier. Sow a little later or space plants closer if you specifically want smaller individual plants.

How can I make lemongrass grow bigger or faster?

Full sun, warm soil and steady water are what drive a crop to full size fastest. Sow at the right time for your zone so it gets the whole season to size up. Feed appropriately for the crop and never let it check (stall) from drought or cold.