How to grow Vietnamese Mint in Australia
Vietnamese mint (Persicaria odorata), also called rau răm, Vietnamese coriander or laksa leaf, is a vigorous, spreading herb with narrow leaves marked with a dark blotch and a hot, peppery, coriander-like flavour. Despite its name it is not a mint but a relative of sorrel and rhubarb, and unlike true coriander it does not bolt in summer heat. It loves warmth, part shade and wet soil, roots from almost any stem, and grows all year in the tropics.
📖 Our full guide: How to Grow Vietnamese Mint in Australia
At a glance
When to sow by region
| Region | When to sow | Regional note |
|---|---|---|
| South East Queensland | September to April | |
| Northern Rivers NSW | September to April | |
| Sydney & Coastal NSW | September to March | Reliable perennial on the frost free coast; grow from cuttings in a damp spot. In the west keep it in a pot you can shelter from frost. |
| Melbourne & Victoria | October to December | Plant Oct to Dec from cuttings or a nursery pot, in part shade with the soil kept wet. Frost kills the tops, so grow it in a pot you can shelter over winter, cut it back after the last frost and it reshoots in spring. |
| Adelaide & SA | October to December | Plant Oct to Dec in a pot kept wet, in part shade. Cold kills the tops, so move the pot under cover for winter. |
| Perth & WA | September to December | Plant Sep to Dec in a pot standing in water, in bright shade. It sulks in the cool wet winter and reshoots in spring. |
| Tasmania | Not suited | Unsuitable outdoors. Frost kills it. A pot moved indoors over winter is the only way. |
| Canberra & ACT | Not suited | Not suited outdoors. It is a tropical herb and Canberra frost kills it. Keep it as a pot plant moved indoors before the first frost, or grow common mint or coriander instead. |
| North Queensland | All year | Grows all year in the tropics. Plant cuttings any month in a damp spot or a pot; use free draining mix so wet season downpours do not rot it, and water often through the dry. |
| Darwin & Top End | All year | Grows all year in the tropics. Plant cuttings any month in a damp spot or a pot; use free draining mix so wet season downpours do not rot it, and water often through the dry. |
Not to be confused with: Mint, which is a different plant with a cool, menthol flavour, and Coriander, which tastes similar but is a cool season annual that runs to seed in summer heat. Vietnamese mint is hotter and more peppery, and keeps growing through summer.
Where to plant
Vietnamese mint likes rich soil that stays moist or even wet, in part shade or full sun with plenty of water. It wilts quickly and its leaves scorch if the soil dries out. It is happy at the edge of a pond or in a pot standing in a saucer of water, and can be used as a groundcover under trees. It spreads by running, rooting stems, so many gardeners grow it in a pot or a contained damp corner.
It is frost tender and slows down or dies back when temperatures drop below about 7°C. In cooler areas the tops are killed by frost, but a sheltered or potted plant usually reshoots in spring.
- North Queensland and Darwin: grows all year. Plant cuttings any month in a damp spot or a pot; use a free-draining mix in the wet season so downpours do not rot it, and water often through the dry.
- South East Queensland and the Northern Rivers: plant from September to April. A reliable perennial in a damp spot.
- Sydney: plant from September to March. Reliable on the frost-free coast; in the west, keep it in a pot you can shelter from frost.
- Melbourne and Adelaide: plant from October to December in part shade, in a pot kept wet, and move it under cover for winter.
- Perth: plant from September to December in a pot standing in water, in bright shade. It sulks in the cool winter and reshoots in spring.
- Hobart and Canberra: not suited outdoors. Grow it in a pot moved indoors before the first frost.
How to plant
- Start from a nursery plant or a cutting. Bought bunches from an Asian grocer often have stems that root readily.
- Remove the lower leaves from 10 to 15 cm stem cuttings and stand them in a glass of water, or push them into moist potting mix. Roots form within a week or two in warm weather.
- Plant in rich, moist soil or a pot of good potting mix, in part shade, about 30 cm apart.
- Water in well and keep the soil constantly moist. Seed is rarely produced outside the tropics, so cuttings are the usual way to grow it.
Watering and feeding
Water frequently and never let the soil dry out. Pots can stand in a saucer of water in hot weather. In the tropical wet season, though, use free-draining mix so constant rain does not rot the roots.
Feed lightly with a nitrogen-rich liquid fertiliser every couple of weeks while it is growing for lush, tender leaves.
Pruning and care through the year
- Pinch and cut often to keep the plant compact and leafy; cut back to firm stems and it soon reshoots.
- Contain it. The stems root wherever they touch moist soil, so grow it in a pot or edge the bed, and pull out wandering runners.
- In cooler areas, cut the plant back in winter or after the last frost to encourage fresh spring growth.
Harvesting
Pick leafy tips once the plant is established and spreading. Pinch or snip stems and it bounces back quickly. The younger leaves have the best flavour. Use them fresh, as they do not dry well.
Stand cut stems in a glass of water in the fridge, loosely covered, or wrap them in a damp cloth, and use within about five days.
Growing in pots
A pot is the easiest way to grow Vietnamese mint, as it keeps the spreading stems in check and lets you move the plant out of frost. Use a pot at least 30 cm wide with good potting mix, keep it wet, and stand it in a saucer of water in summer.
Using it
Use fresh leaves in Vietnamese and South East Asian dishes: in rice paper rolls, salads, pho and other noodle soups, and with chicken, fish and eggs. It is an essential ingredient of laksa in Malaysia, Singapore and Indonesia, which is why it is also called laksa leaf. Add it at the end of cooking. Its strong, peppery flavour makes a good substitute for coriander in hot weather, when coriander bolts.
Propagation
Vietnamese mint rarely sets seed and is grown from cuttings. Almost any stem with a node will root in water or moist soil within a week or two in warm weather. Runners that have rooted can be dug up and replanted.
Companion planting
Because it spreads so readily, Vietnamese mint is best kept in a pot or its own damp corner rather than mixed into a vegie bed. It suits a damp, part-shaded spot beside other warm climate Asian herbs and vegetables.
Good companions
Pests and diseases
Vietnamese mint has few pests. Dry soil and cold cause more trouble than insects.
Vietnamese Mint is rarely troubled by pests.
Diseases to watch for
- Rust Small orange or brown pustules under the leaves. Cut back affected stems and let them regrow.
Common questions
Is Vietnamese mint the same as rau răm or Vietnamese coriander?
Yes. Vietnamese mint, rau răm, Vietnamese coriander and laksa leaf are all names for the same plant, Persicaria odorata. It is neither a true mint nor a true coriander.
Is Vietnamese mint a real mint?
No. Despite the name, Vietnamese mint (Persicaria odorata) is in the same family as buckwheat, sorrel and rhubarb. It tastes peppery and spicy rather than minty.
How do I grow Vietnamese mint from cuttings?
Remove the lower leaves from 10 to 15 cm stems and stand them in a glass of water or push them into moist potting mix. Roots form within a week or two in warm weather. Bought bunches often root this way.
Why are my Vietnamese mint leaves turning brown?
Usually dry soil or cold. It needs constantly moist to wet soil and wilts and scorches quickly when dry. Frost kills the tops, and growth stalls below about 7°C.
Does Vietnamese mint spread?
Yes. Its stems root wherever they touch moist soil, so it can spread widely. Growing it in a pot keeps it under control.
Can Vietnamese mint replace coriander?
In many dishes, yes. It has a similar, stronger flavour and keeps growing through hot weather when coriander bolts.
Can Vietnamese mint grow in shade?
Yes. Part shade suits it best, especially in hot areas. In deep shade it grows more slowly.
Will Vietnamese mint survive winter?
In frost-free areas it grows all year. In frosty areas the tops die back; keep it in a pot that can be moved under cover, and cut it back after the last frost so it reshoots.
Sources we checked: Yates: How to grow Vietnamese mint; Gardening Australia: FAQs, Vietnamese mint; Wikipedia: Persicaria odorata (Vietnamese coriander; cultivation, temperatures, propagation).