Bok choy, also known as pak choy, are one of a group of leafy green vegetables that come under the umbrella of Asian greens – fast-growing leafy vegetables favoured in Asian cuisine.

It is part of the large brassica or mustard family (Brassicaceae). These plants are a boon for gardeners in a hurry as they are quick and easy to grow and just as easy to cook in a quick stir-fry or as a bowl of steamed vegetables. Bok choy has been cultivated in China since at least the 5th century AD.

There are two main forms of bok choy (known botanically as Brassica rapa ‘Chinensis’) grown in vegetable gardens. A form with thick, bright white stems and dark green leaves while another form has dark, purple-toned leaves.

Follow our seven easy steps to successful bok choy harvest including tips along the way.

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When to plant

Like other brassicas, bok choy does best in a mild climate but is also worth growing through winter and early spring in warm temperate, subtropical and tropical climates. Check with hardware and garden centres for advice on your local conditions.

It can be slow to germinate in very cold or very hot conditions.
Protect young seedlings from heavy frost. In the cooler parts of southern Australia delay planting until August.
In warm zones, plant in autumn or winter; avoid planting in the middle of summer.

Location

Plants grow best in full sun or with light afternoon shade in hotter temperatures.
They will flourish in soil that holds moisture well.
In crop rotation, bok choy and other brassicas can follow legumes.
They can also be grown in large containers if space is limited.

Soil

Get the soil right to harvest a bumper harvest of juicy bok choy.

Follow our steps for easy soil preparation.

Bok choy does best in a neutral to slightly alkaline soil, so adding lime before planting is beneficial and ensures good growth.
Dig in extra well-rotted organic matter such as compost, well-rotted manure and/or Seasol Super Compost.
A soil rich in nutrients helps build strong plants, so add Seasol Plant + Soil Booster (100g per square metre) and a fertiliser such as PowerFeed Controlled Release for Tomatoes & Vegetables.
Water in well and let the soil rest for a week or two before planting.

Step 1 – Sowing seeds

Grow from seed sown directly into moist, well-prepared soil or seed raising mix such as Seasol Seed Raising & Cutting Potting Mix.
Sow at a depth of 6mm and space 5-20cm apart in rows 25cm apart.
Water in well with Seasol GOLD or Seasol (mix 30mL concentrate per 9 litres of water) as this will help to increase seed germination rates.
Soil should be moist but not wet, so check the soil moisture daily to ensure the seeds have the right conditions to germinate.

Note: Images above are not bok choy seeds, it’s an illustration to show seeds being sown.

Step 2 – Germination

Expect germination in 6-10 days (although it maybe slower in very hot or cold conditions). Watch for the tiny leaves to come through the soil.
When bok choy germinates, each seedling has two leaves. These seedling leaves look like two narrow leaves on either side of the stem.
Gently thin the tiny seedlings to 15-20cm apart when they are about 5cm high to reduce overcrowding and poor root development.
Water gently and apply Seasol GOLD or Seasol weekly for strong healthy root development and growth.

Step 3 – Baby bok choy seedlings

Transplant seedlings growing in cells or trays into small individual pots when they are big enough to handle. Allow them to grow on until they are ready to be planted out into the garden.
Keep young bok choy seedlings moist.
Protect emerging seedlings from snails and slugs that like to eat on the juicy, young foliage and can destroy crops. (See ‘Things to watch out for’ below for more advice.)
Apply a liquid fertiliser such as PowerFeed PRO SERIES for Tomatoes & Vegetables for strong healthy growth as plants mature.

Step 4 – Transplant bok choy seedlings

Transplant seedlings when they are around 7cm high spacing seedlings 20cm apart to allow for good stem and leaf formation.
If transplanting purchased seedlings, plant in the same way as above, following the directions on the plant tag.
Push the soil firmly around the roots of the seedling, but don’t push down hard as this can compact the soil around the root zone stopping good root development.
Water your newly transplanted seedlings in with Seasol GOLD or Seasol to aid plant establishment and strong healthy growth.

Step 5 – Bok choy plant growth

Keep the area around each plant hand weeded or lightly hoed, as weeds compete for space, moisture and nutrients.
Water well and spread mulch around each plant to suppress weeds, help retain soil moisture.
As you watch your bok choy grow over the following weeks you will see the white stem thickening and strong leaf growth. Young leaves can be harvested taking a few from the outside of the plant.
Every 6-8 weeks apply PowerFeed Controlled Release for Tomatoes & Vegetables to produce a bumper crop. Mix into the topsoil and water it in after application.

Step 6 – Mature bok choy growth

As the plant grows it forms a large plant with strong white overlapping stems and large dark green or purple green leaves.
Check soil moisture and keep plants well watered for quick growth and the best flavour. Apply water to the soil, not foliage early morning, to avoid wet leaves as this can cause rot.
Apply liquid PowerFeed PRO SERIES for Tomatoes & Vegetables every week to a fortnight for strong healthy growth.
Check mulch around plants and top up where necessary, ensuring to keep it about 5cm-10cm from the base of the plant.

Step 7 – Bok choy harvest

Harvest bok choy as the plant forms a good size with thick stems usually 7- 10 weeks after planting.
As bok choy can regrow, it is possible to harvest up to half the plant, which encourages new leaf growth.
To harvest cut at the base of the stem. Wash and store in a plastic bag in the crisper section of the refrigerator for up to a week.

Note: Bok choy that is heat or water stressed or over mature becomes strongly peppery. Cutting back over mature plants may encourage a new crop of leaves. Alternatively plants that are over mature can be left to grow and flower to attract pollinators and beneficial insects to the vegetable patch and for seed.

Things to watch out for

Aphids These tiny black or green pests cluster under leaves. Squash or hose off.
Cabbage white butterflies The green caterpillars of this small white butterfly feed on all brassicas. Squash any seen or apply EarthCare Enviro Pest Oil insect spray. Erecting netted tunnels over the rows prevents this pest from laying eggs on the leaves of the crop.
Slugs and snails These pests can destroy young plants. Snails and slugs are active at night. Remove by hand.
Club root This is a fungal disease that affects growth and causes distorted swollen roots. Applying lime before planting reduces the likelihood of this disease. This is particularly important in acidic soils.
Downy mildew This fungus can attack leaves. Look for yellowing discolouration above and white mildew below the leaves. Remove affected leaves.