How to grow Tatsoi in New Zealand
Tatsoi forms a flat, attractive rosette of small, dark green, spoon-shaped leaves with a mild mustard flavour. It is fast, handles cool weather well and is one of the best Asian greens for growing through winter. Pick the outer leaves young for salads, or cook them lightly in stir-fries and soups.
📖 Our full guide: How to Grow Tatsoi in New Zealand
At a glance
When to sow by region
| Region | When to sow | Regional note |
|---|---|---|
| Northland | February to April, August to October | |
| Auckland | February to April, August to October | |
| Waikato & Bay of Plenty | February to April, August to October | |
| Central North Island | February to April, September and October | Skip August in the central North Island. Hard frosts and cold soil stall seedlings, so start in September, under a cloche if you can. |
| Wellington & Lower North Island | February to April, August to October | |
| Nelson & Marlborough | February to April, August to October | |
| Canterbury | February and March, September to November | Start spring sowings in Sep under a cloche or frost cloth, as frosts run to mid October. Keep sowing through Nov with steady watering. Make the last sowing in Mar so the crop is ready before winter growth stops. |
| Otago & Southland | February and March, October and November | Start spring sowings in Oct under a cloche or frost cloth, as frosts run to late October. Cool summers let you keep sowing through Nov. Make the last sowing in Mar so the crop is ready before winter growth stops. |
| Central Otago | February and March, October | Start spring sowings in Oct under a cloche or frost cloth, as frosts run into early November. Make the last sowing in Mar so the crop is ready before winter growth stops. |
Not to be confused with: Bok choy, a close relative with upright, thick white stems, and mizuna and komatsuna, other leafy Asian brassicas.
Where to plant
Tatsoi grows best in the cooler months, when leafy growth is strong and plants are less likely to bolt. Give it full sun in winter, and in warmer weather a spot with morning sun and afternoon shade. It grows quickly, so rich, well-prepared soil makes a real difference.
- Northland, Auckland, Waikato, the Bay of Plenty, Wellington and Nelson: sow from late summer through autumn and again from late winter into early spring.
- Central North Island: skip August, as hard frosts and cold soil stall seedlings; start again in September, under a cloche if you can.
- Canterbury: start spring sowings in September under a cloche or frost cloth, keep sowing into November, and make the last autumn sowing in March.
- Otago, Southland and Central Otago: start spring sowings in October under a cloche, and make the last sowing in March.
How to plant
- Loosen the soil and dig in compost and a little sheep pellets or vegetable fertiliser.
- Sow seed thinly, cover lightly, firm down and water well, or plant seedlings at the depth they grew in the punnet.
- Space plants about 20 cm apart.
- Plant a few more every two to three weeks for a steady supply.
Watering and feeding
Keep the soil evenly moist but never waterlogged; dry soil makes the leaves tough and bitter and triggers bolting. Water at the base rather than over the leaves, and mulch lightly to hold moisture. Work a vegetable fertiliser into the soil before planting and side dress lightly if growth slows or leaves look pale. Avoid heavy nitrogen close to harvest, which makes leaves soft and more attractive to pests.
Pruning and care through the year
- Cover young plants with fine insect netting from spring to autumn to keep white butterflies off.
- Check for slugs and snails after rain, and clear away old leaves where they hide.
- Pull plants once they start to bolt, as the leaves turn tough and strong.
Harvesting
Pick outer leaves as soon as they are big enough, which keeps the plant producing, or cut the whole rosette at the base once it is full sized. Leaving mature plants too long makes the leaves tougher and stronger flavoured.
Growing in pots
Tatsoi is ideal for pots and troughs. Use a vegetable mix rather than garden soil, which compacts in pots, check the moisture often, and refresh the mix between crops.
Varieties
- Tatsoi
Companion planting
Tatsoi is small and quick, and fits between slower crops.
Good companions
Pests and diseases
As brassicas, Asian greens share cabbage pests. Slugs and snails are the main problem in damp autumn and winter weather.
Pests to watch for
- Slugs and snails (slugs and snails) Ragged holes and missing seedlings, especially in damp weather. Check in the evening and after rain.
- White butterfly Green caterpillars and holes in leaves from spring to autumn. Cover young crops with fine insect netting.
- Aphids Clusters of grey-green insects on new growth and under leaves.
- Slugs
Diseases to watch for
- Downy mildew Yellow patches on leaves with grey growth underneath in cool, damp weather.
Common questions
When should I grow tatsoi in New Zealand?
In the cooler months. In warm areas, sow from late summer to early spring; in cool areas, from February to July and again in spring. Choose your region at the top of the page.
How do I harvest tatsoi?
Pick the outer leaves while young and tender, or cut the whole rosette at the base when it is full sized.
Why has my tatsoi gone to seed?
Warm weather, long days and dry soil make it bolt. Grow it in the cool months, keep the soil evenly moist, and give it afternoon shade as the weather warms.
Can I eat tatsoi raw?
Yes. Young leaves are mild and good in salads; older leaves are better lightly cooked.
What is eating my tatsoi?
Usually slugs and snails in damp weather, or white butterfly caterpillars in warmer months. Check plants in the evening and cover young crops with fine netting.
Sources we checked: Daltons: How to grow Asian greens; Yates NZ: How to grow Asian greens.