Bok choy (pak choi)

Sun

Full sun in cool weather; light afternoon shade in warmer conditions.

Water

Keep soil evenly moist, watering thoroughly whenever the surface starts to dry; avoid waterlogging.

Soil

Fertile, moisture-retentive but well-drained soil, ideally pH 6.0-7.5.

Height

0.5-1.5 ft (0.15-0.45 m) before flowering

Spread

0.5-1 ft (0.15-0.3 m)

Foliage

Loose, upright rosettes of smooth green leaves with broad, fleshy white or pale green leaf stalks.

Growth

Fast; baby leaves are often ready in about 3-4 weeks and full rosettes in 5-8 weeks, depending on variety and weather.

Care needed

Medium

• Edible

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Needs looking after

Pick your zone, country, light and whether you have pets.

1. Planting day

   0.5 ft (0.15 m)

2. After 1 year

   1 ft (0.3 m)

   full size

Full size in one season.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Growth rate

Fast

• Mix mature compost into the bed before sowing or planting.
• Thin plants to 6-12 in (15-30 cm) apart, depending on the variety and intended harvest size.
• Water consistently; drought stress makes leaves tougher and encourages bolting.
• Apply a thin mulch once seedlings are established, keeping it clear of their crowns.
• Cover seedlings with insect mesh, securing the edges to exclude flea beetles and cabbage butterflies.
• In poor soil or containers, apply a balanced liquid vegetable feed according to the label.

Pruning. No routine pruning is needed. Remove damaged or yellowing leaves promptly, and harvest plants as soon as flower stems begin to develop.

Pick outer leaves once they are large enough to use, leaving the central growing point intact, or cut the whole rosette at soil level when the stalks are plump and the leaves are tender. Baby plants can be harvested after about 3-4 weeks; full-sized plants usually take 5-8 weeks, and are best picked before a central flower stem rises.

Early spring

Prepare beds with compost; sow under cover if outdoor conditions are still cold.

Mid-spring

Sow outdoors or plant out hardened-off seedlings once soil is warming; avoid exposing young plants to prolonged cold.

Late spring

Harvest spring crops promptly and check beneath leaves for caterpillars.

Summer

In hot weather, pause sowing or use a lightly shaded position and maintain even moisture.

Late summer

Sow the main autumn crop, allowing roughly 6-8 weeks before regular hard frosts.

Autumn

Harvest regularly; use fleece or a cold frame to extend cropping through light frosts.

Winter

In mild climates, harvest protected crops; elsewhere remove spent plants and plan crop rotation.

• Plant in short, repeated rows in a potager for a clear pattern of upright green rosettes.
• Use compact varieties in balcony pots or raised planters close to the kitchen.
• Edge vegetable beds with baby-leaf plants for a low, harvestable border.
• Pair with loose-leaf lettuce and spring onions for contrasting leaf shapes in an edible display.

Garden styles it suits: Potager (kitchen garden), Edible landscape, Homestead, Small-space, Modern courtyard and Family-friendly.

Plant it with: Lettuce, Spring onions, Coriander, Spinach and Carrots.

Wildlife: Leaves feed several cabbage-family insects. If allowed to flower, the yellow flowers provide nectar and pollen for bees and hoverflies.

• Flea beetles chew small holes in young leaves: cover immediately after sowing with fine insect mesh and keep seedlings growing steadily.
• Slugs and snails damage seedlings and leaf stalks: check after dark, remove hiding places, and use labelled iron phosphate bait where needed.
• Cabbage caterpillars strip leaves: inspect leaf undersides for eggs and larvae, remove them by hand, and use well-secured insect mesh.
• Bolting produces a central flower stem and poorer-quality leaves: avoid prolonged chilling of seedlings, heat and drought stress; favour late-summer sowing and harvest promptly.

Not known to be toxic to people, cats, dogs or horses in ordinary food quantities; the leaves and stalks are edible. Large amounts may cause digestive upset, and sustained excessive intake of raw brassicas can interfere with thyroid function.

• Choy sum (Brassica rapa var. parachinensis)

  Usually grown for slender flowering stems with small leaves and yellow buds, rather than the broad, fleshy stalks and basal rosette of bok choy.

• Napa cabbage (Brassica rapa subsp. pekinensis)

  Forms an elongated, compact head of crinkled leaves; bok choy forms an open rosette with distinct spoon-shaped leaves.

• Tatsoi (Brassica rapa subsp. narinosa)

  Typically forms a low, spreading rosette of smaller, dark green, spoon-shaped leaves with narrower stalks.

Bok choy comes from Cantonese words meaning 'white vegetable', referring to its pale leaf stalks.

Propagation. Grow from seed, sown about 0.25-0.5 in (0.5-1 cm) deep directly where it will grow, or in modules for transplanting while young. Make small repeat sowings during suitable cool weather; saved seed may cross with other flowering Brassica rapa crops.

Accepted botanical name

Brassica rapa Brassica rapa subsp. chinensis is an older name for Brassica rapa.

In the US and Canada

Introduced in Alaska, Canada, Greenland, Hawaii and the lower 48 states.

Native range

Albania, Algeria, Bulgaria, Eritrea, Ethiopia, Greece, Iran, Iraq, Italy, Kriti, Lebanon-Syria and Libya.

Measured

Soil pH 5 to 8. Average height 80 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.