How to grow Bok Choy in New Zealand
Bok choy, also sold as pak choi, is a fast Asian green with crisp stems and tender leaves, ready to cut in about six to eight weeks. It grows best in the cooler halves of the year, spring and autumn, because heat and long days make it bolt to flower. Sow little and often for a steady supply.
📖 Our full guide: How to Grow Bok Choy 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 to April, August to November | Sow Aug to Nov and Feb to Apr. Cover early sowings with a cloche or frost cloth, as frosts run to mid October. Get the last sowing in by Apr so it sizes up before winter growth stops. |
| Otago & Southland | February to April, September to November | Sow Sep to Nov and Feb to Apr. Cover early sowings with a cloche or frost cloth, as frosts run to late October. Get the last sowing in by Apr so it sizes up before winter growth stops. |
| Central Otago | February to April, September and October | Sow Sep to Oct and Feb to Apr. Cover early sowings with a cloche or frost cloth, as frosts run to early November. Get the last sowing in by Apr so it sizes up before winter growth stops. |
Where to plant
Grow bok choy in fertile, moist, well-drained soil enriched with compost. It likes full sun in the cool seasons, but light afternoon shade helps late spring sowings stay leafy for longer. As a member of the cabbage family, it should not follow other brassicas in the same bed, to avoid clubroot.
- Northland, Auckland, Waikato and Bay of Plenty, Wellington, and Nelson and Marlborough: sow from August to October and again from February to April.
- Central North Island: skip August, as hard frosts and cold soil stall seedlings. Sow from September to October and February to April.
- Canterbury: sow from August to November and February to April, covering early sowings with a cloche or frost cloth, as frosts run to mid October.
- Otago and Southland: sow from September to November and February to April, with early sowings under a cloche. Get the last sowing in by April.
- Central Otago: sow in September and October and from February to April, covering early sowings, as frosts run into early November.
Choosing a variety
- White Stem pak choi: the classic crisp white-stemmed type with dark green leaves. Do not sow too early in cool areas, as cold can trigger bolting.
- Shanghai Green: compact, vase-shaped heads with pale green stems, good harvested young as baby choi and in containers.
- Hybrids such as Green Ace and Mei Qing Choi are bred for uniform heads.
How to plant
- Work compost or blood and bone into the bed.
- Sow seed directly where it is to grow, about 3 to 5 mm deep. Bok choy tends to bolt if transplanted, so direct sowing is best.
- Keep the soil moist; seedlings appear in 5 to 10 days.
- Thin to 15 to 20 cm apart, or closer for baby choi, and eat the thinnings.
- Cover the bed with insect mesh straight after sowing to keep white butterfly off.
Watering and feeding
Keep the soil evenly moist. Dry spells check growth and make the plants bolt and turn bitter.
A liquid feed every week or two keeps the leaves growing quickly and tender.
Pruning and care through the year
- Make a small sowing every few weeks for a continuous harvest.
- Keep insect mesh over the crop while white butterfly is active in spring, summer and autumn.
- Pull plants promptly if they start to send up a flower stalk.
Harvesting
Cut whole heads at the base once they are well formed, about 45 to 60 days from sowing, or pick a few outer leaves at a time for a longer harvest. Baby choi can be cut much younger.
If a plant starts to bolt, the young flower shoots are tender and good in stir-fries. Bok choy keeps up to four days in a sealed bag in the fridge.
Growing in pots
Bok choy grows well in a pot or trough at least 25 cm deep, in quality potting mix. Sow directly into the pot, keep it moist and feed every week or two. Shanghai types are a good choice for containers.
Using it
Stir-fry, steam or braise whole heads or halves, add leaves to soups and noodles, or eat young leaves raw in salads.
Companion planting
Bok choy is quick, so it fits between slower crops.
Good companions
- Beetroot A root crop that shares the bed without competing for the same space.
- Celery Both like cool, moist, fertile soil.
Keep apart
Avoid planting these close to bok choy.
- Tomato Tomatoes are a summer crop that shades and crowds bok choy, which grows in the cool seasons.
Pests and diseases
Caterpillars of the white butterfly and slugs are the main pests. Insect mesh solves most problems.
Pests to watch for
- White butterfly Green caterpillars and chewed holes in the leaves. Cover with insect mesh.
- Diamondback moth Small green caterpillars that wriggle when touched, and leaves with small holes and windows.
- Slugs Large, ragged holes and silvery slime trails, especially on seedlings.
- Snails Ragged holes in leaves after damp nights.
- Aphids Clusters of grey or green insects under the leaves and in the heart.
Diseases to watch for
Common questions
Why does my bok choy bolt?
Heat, long days, dry soil, transplanting and cold snaps in very early sowings can all trigger bolting. Sow directly in spring or autumn, keep the soil moist, and harvest promptly.
When should I sow bok choy in New Zealand?
In the cooler parts of the year: August to October and February to April in most regions. In the south, start in September and cover early sowings.
How long does bok choy take to grow?
About 45 to 60 days from sowing to full heads. Baby choi can be cut sooner.
How do I stop caterpillars on bok choy?
Cover the crop with fine insect mesh from sowing, so white butterflies and diamondback moths cannot lay eggs on it.
Can I harvest bok choy more than once?
Yes. Pick a few outer leaves at a time instead of cutting the whole head, and the plant keeps growing.
Is pak choi the same as bok choy?
Yes, they are two spellings of the same vegetable.
Sources we checked: Yates NZ: How to grow Asian greens; Yates NZ: Common problems of Asian greens; Kings Seeds: Pak Choi White Stem; Kings Seeds: Organic Pak Choi Shanghai Green.