Mature size & growth rate

How big does Citronella Grass (Cymbopogon nardus) get?

Also called Citronella Grass, Nardus Grass, Sri Lanka Lemongrass.

More about citronella grass

About Citronella Grass

Cymbopogon nardus · also called Citronella Grass, Nardus Grass · herb

Citronella Grass is a large, clump-forming tropical grass native to South and Southeast Asia, grown commercially as the source of true citronella essential oil used in insect repellents and perfumery. It produces tall, graceful, blue-green arching leaves with a strong citrus-like scent when crushed. In temperate climates it is grown as a tender annual or container specimen.

Mature size: 1.5–2 m tall, 1–1.5 m wide (5–6.5 ft tall, 3–5 ft wide)

Watch for — Pot-bound crowding / loss of vigour: Citronella grass is a vigorous grower that rapidly fills and splits containers. Root-bound plants produce less foliage and dry out extremely quickly. Repot into a container one or two sizes larger each spring, or divide the clump — separate the dense rhizomatous base with a sharp spade or saw and replant sections in fresh compost.

Indoor size vs how big it gets in the wild

Citronella Grass grows on a tree's timeline and scale — indoors it becomes a tall, trunked statement plant rather than a tabletop one. Indoors and in a pot, expect 1.5–2 m tall, 1–1.5 m wide (5–6.5 ft tall, 3–5 ft 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 gains real height on a trunk or main stem, adding a tier of leaves a year and eventually reaching for the ceiling — this is a plant you grow up, not out.

Growth rate and years to mature

Citronella Grass is a moderate grower. Realistically, expect three to six years to reach mature indoor size, gaining a steady amount each growing season. Its feeding profile backs this up: feed with a balanced, nitrogen-rich fertiliser (e.g. general-purpose 10-10-10 or a grass fertiliser) monthly from spring through late summer to support rapid foliage growth. in containers, where nutrients deplete faster, a monthly liquid feed at half to full strength during the growing season is recommended. withhold feeding entirely during winter when growth is minimal.

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

How to keep citronella grass smaller

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

The decisive tool is the secateurs: citronella grass can be topped (cut the main growing tip) to cap its height and force a bushier, shorter shape.
Keeping it deliberately pot-bound in a snug container slows the whole plant and limits ultimate size.
Prune in spring so it heals fast; remove the tallest leader back to a node to reset the height.
Expect to top or hard-prune it every year or two — left alone it heads for the ceiling.

The keep-it-smaller method, step by step

Pick the new height. Decide how tall you want citronella grass and find a leaf node or branch point just below that.
Top the main stem. Cut the main growing tip cleanly just above that node in spring; this permanently caps the height and forces side branches.
Keep the pot snug. Avoid jumping to a much bigger pot — a slightly restricted rootball keeps the whole plant smaller.
Maintain the shape. Prune back the tallest new leaders each spring to hold it at the height you chose.

How to grow citronella grass bigger or faster

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

It already wants the bright light it needs; warmth, a yearly pot-up and spring-summer feed are the accelerators.
Pot up a size every year or two while young; restricted roots are the main thing holding height back.
Feed regularly through the growing season and keep it warm — height comes from sustained good conditions.

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

When citronella grass outgrows the room (or the pot)

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

The top leaves pressing against or bent by the ceiling — the classic "this is now too tall indoors" sign.
It has to be moved away from a light source it has literally outgrown.
Roots filling the largest pot you can reasonably keep indoors — at that point it is top-or-prune or move it outside (if hardy).

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

Citronella Grass size — frequently asked questions

How big does citronella grass get?

Citronella Grass reaches 1.5–2 m tall, 1–1.5 m wide (5–6.5 ft tall, 3–5 ft wide) when grown indoors. It gains real height on a trunk or main stem, adding a tier of leaves a year and eventually reaching for the ceiling — this is a plant you grow up, not out.

Is citronella grass slow or fast growing?

Citronella Grass is a moderate grower. Expect three to six years to reach mature indoor size, gaining a steady amount each growing season. Citronella Grass grows on a tree's timeline and scale — indoors it becomes a tall, trunked statement plant rather than a tabletop one.

How long does citronella grass take to reach full size?

Roughly three to six years to reach mature indoor size, gaining a steady amount each growing season. Light, pot size and feeding move that timeline more than anything else.

How do I keep citronella grass smaller?

The decisive tool is the secateurs: citronella grass can be topped (cut the main growing tip) to cap its height and force a bushier, shorter shape. Keeping it deliberately pot-bound in a snug container slows the whole plant and limits ultimate size. Prune in spring so it heals fast; remove the tallest leader back to a node to reset the height. Expect to top or hard-prune it every year or two — left alone it heads for the ceiling.

How can I make citronella grass grow bigger or faster?

It already wants the bright light it needs; warmth, a yearly pot-up and spring-summer feed are the accelerators. Pot up a size every year or two while young; restricted roots are the main thing holding height back. Feed regularly through the growing season and keep it warm — height comes from sustained good conditions.