Watering schedule
How often to water Vietnamese Coriander (Persicaria odorata) — the schedule
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.
Ideal humidity: Moderate to high (50%+)
Watch for — Wilting / leaf collapse: The most common complaint, almost always from the soil drying out. This water-loving herb flops fast when thirsty but usually perks back up within hours of a thorough watering. Keep it consistently moist.
The watering schedule, season by season
Vietnamese Coriander 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 vietnamese coriander is keep soil consistently moist to wet; water container plants daily in warm weather, 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.
This is a marsh-margin plant with high water needs that never wants to dry out. Keep the soil consistently moist to wet but avoid stagnant waterlogging. It wilts quickly when underwatered but recovers fast once rehydrated. Containers dry out faster and may need daily watering in heat.
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 vietnamese coriander in seconds.
How to tell vietnamese coriander needs water
A calendar is the worst way to water vietnamese coriander. 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 vietnamese coriander for a day is almost always safer than over-watering it.
Overwatering vs underwatering vietnamese coriander
The two failure modes can look alike at a glance, so check the soil weight and wetness before you decide. For vietnamese coriander 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 vietnamese coriander 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 vietnamese coriander; frequency and consistency matter, not water type.
Seasonal and environmental adjusters
Every figure above shifts with the conditions in your home. For vietnamese coriander, 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 vietnamese coriander.
Vietnamese Coriander watering — frequently asked questions
How often should I water vietnamese coriander?
Water vietnamese coriander keep soil consistently moist to wet; water container plants daily in warm weather. 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 vietnamese coriander 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 vietnamese coriander is the first signal on that list — checking the soil or the plant directly always beats watering by the calendar.
What does an overwatered vietnamese coriander 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 vietnamese coriander 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 vietnamese coriander?
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 vietnamese coriander?
Tap water is fine for vietnamese coriander; frequency and consistency matter, not water type.
Keep reading
- Watering vietnamese coriander in the UK — hard vs soft tap water
- Vietnamese Coriander care — the full brief (light, soil, humidity, problems, pet safety)
- Watering calculator — get a starting interval for your exact pot and light
- Pot size calculator — the right pot keeps watering forgiving
- Why is my plant wilting? Wet vs dry diagnosis
- Underwatered plant — signs and how to rehydrate it
- Should I water my plant? The simple check before you pour
- How often to water basil
- How often to water herb garden
- How often to water mint
- All 609 watering schedules in the Growli library