Mature size & growth rate

How big does Vietnamese Coriander (Persicaria odorata) get?

Also called Vietnamese coriander, Vietnamese mint, rau ram, Cambodian mint, laksa leaf, Asian mint.

More about vietnamese coriander

About Vietnamese Coriander

Persicaria odorata · also called Vietnamese coriander, Vietnamese mint · herb

Vietnamese coriander (Persicaria odorata), or rau ram, is a heat-loving Southeast Asian culinary herb with a peppery, cilantro-like flavour that does not bolt in summer heat. Give it bright light, constantly moist soil and warmth. Not listed by the ASPCA, but related buckwheat-family plants are toxic, so verify with your vet.

Mature size: Roughly 15-45 cm (6-18 in) tall and a similar or wider spread; stems trail and root as they spread, so plants stay low and bushy rather than tall.

Watch for — Aphids: Soft-bodied sap-suckers that cluster on tender new growth. Dislodge them with a firm spray of water; for heavier infestations use insecticidal soap, rinsing edible leaves well before use.

Indoor size vs how big it gets in the wild

Vietnamese Coriander 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 roughly 15-45 cm (6-18 in) tall and a similar or wider spread. In the ground with no restriction it is a completely different plant — stems trail and root as they spread, so plants stay low and bushy rather than tall. — which is why the pot, the light and the pruning matter so much for the size you actually end up with.

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

Vietnamese Coriander 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: feed with a balanced or nitrogen-leaning fertiliser about twice a month during the warm growing season and roughly once a month in cooler periods. container plants need more frequent feeding because nutrients leach out with regular watering. avoid over-fertilising, which can dilute the leaves' aromatic, peppery flavour.

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

How to keep vietnamese coriander smaller

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

Choose a compact or dwarf variety of vietnamese coriander 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 vietnamese coriander bigger or faster

If you want it to fill the space sooner, push the conditions rather than hoping — for vietnamese coriander 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 vietnamese coriander light requirements page covers exactly how bright a spot it needs to grow at its potential instead of stalling.

When vietnamese coriander outgrows the room (or the pot)

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

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 vietnamese coriander repotting guide. If you want more of this plant instead of a bigger one, the vietnamese coriander propagation guide turns prunings into new plants.

Vietnamese Coriander size — frequently asked questions

How big does vietnamese coriander get?

Vietnamese Coriander reaches roughly 15-45 cm (6-18 in) tall and a similar or wider spread when grown indoors, and far larger where it grows unrestricted (stems trail and root as they spread, so plants stay low and bushy rather than tall.). 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 vietnamese coriander slow or fast growing?

Vietnamese Coriander is a moderate grower. Expect a single growing season — it reaches full size in one year, then is done. Vietnamese Coriander 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 vietnamese coriander 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 vietnamese coriander smaller?

Choose a compact or dwarf variety of vietnamese coriander 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 vietnamese coriander 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.