When to plant bok choyin Sydney.

Growing bok choy in Sydney: the specifics

Sydney sits in a warm-temperate zone with mild winters, hot summers, and year-round growing potential. Frosts are rare in coastal suburbs but can occur inland west of the Blue Mountains. The mild climate means Sydney gardeners can grow almost anything, summers are ideal for tomatoes, capsicum, and cucumbers, while winters deliver excellent brassicas, leafy greens, and root vegetables. For bok choy, the productive window in Sydney is february-may, august-november. Within that window, Bok choy is a cool-season brassica that grows rapidly and is one of the most satisfying quick-turnaround crops in the raised bed garden. In Australian conditions, it thrives in autumn, winter, and spring, and can be grown in the cooler months in subtropical and tropical climates. Sow seeds direct 5mm deep in rows 30cm apart, or start in seedling trays and transplant when seedlings have 2-3 true leaves (3-4 weeks). Transplanting is generally successful with bok choy, unlike some brassicas, provided roots are not disturbed and seedlings are well-watered in. Thin or plant seedlings to 20cm spacing for full-size heads. For baby bok choy (harvested at 10-15cm), sow densely and harvest alternates to let remaining plants grow on. Bok choy grows best in rich, moisture-retentive soil. Feed with a high-nitrogen liquid fertiliser every 2 weeks, nitrogen produces lush, tender leaves. Mulch around plants to retain moisture and keep roots cool. Consistent moisture is critical; drought stress immediately triggers bolting. Sow every 3-4 weeks through the cool season for continuous supply, this is one of the easiest crops to succession plant because of its speed and reliability. In subtropical climates, autumn, winter, and spring sowing avoids both the high heat of summer and the possibility of bolting in very short-day winter conditions.

Sizing it for your household

Plant 12-16 plants in succession for a family of 4; sow a new batch every 3 weeks through the cool season 200-600g per plant depending on size at harvest. Plant Planner does this maths automatically once you tell it your household size, it’s the part most planners get wrong because they assume every household is the same.

The 20 cm spacing (with 30 cm between rows) means a standard 1.2 m × 2.4 m raised bed in Sydney can hold 48 bok choy plants at maximum density, though in practice you’ll want to mix companions in, so plan for roughly 60-70% of that.

Companion plants for Sydney

Good companions for bok choy include Dill, Marigold, Celery, Beetroot. In Sydney’s temperate climate, these pairings reduce pest pressure and improve pollination. Keep bok choy away from Tomato, Pepper, Fennel, they fight for the same nutrients or attract shared pests.

Sydney-specific tips

• Sydney's wet summers (November-February) bring fungal diseases, ensure beds have excellent drainage and space plants for airflow around tomatoes and zucchini.
• Coastal Sydney rarely frosts, so you can grow silverbeet, kale, and Asian greens year-round without frost protection.
• The summer humidity makes basil bolt quickly, pinch flowers regularly and grow heat-tolerant varieties like Italian Large Leaf.

Common problems

Cabbage white butterfly caterpillars are the primary pest, use fine insect exclusion netting or Bt spray. Use netting from the moment of transplanting for best results. Flea beetles create small round holes in leaves, minor damage does not affect yield significantly. Aphids cluster on young plants; treat with insecticidal soap. Club root is a soilborne disease affecting all brassicas, maintain pH above 7.0 and practice 4-year crop rotation in affected beds.

Harvest

Harvest bok choy by cutting the whole plant at the base when it has formed a compact head. Baby bok choy is harvested at 10-15cm; full-size at 25-35cm. Alternatively, harvest outer leaves individually for a cut-and-come-again approach, plants can produce for 4-6 weeks this way. For the sweetest flavour, harvest in the morning after a cold night.