How to Grow Bok Choy

Bok choy (also spelled pak choi) is a cool-season Asian brassica prized for its crisp white stalks and tender dark green leaves. It grows remarkably fast — baby bok choy heads are ready in as little as 30 days — and is one of the most productive plants per square foot in a cool-season garden. Its mild, slightly sweet flavor suits stir-fries, soups, and raw preparations equally well.

Like all brassicas, bok choy bolts readily in heat and long days. The ideal growing conditions are cool temperatures of 55–75°F with consistently moist soil. Timing is the key challenge: plant too early in spring and a late frost stunts it; plant too late and heat triggers bolting. The fall season, with decreasing temperatures and shortening days, generally produces the best quality and longest harvest window.

Growing Tips

Harvest the entire head before bolting by cutting at soil level, leaving the root intact — in cool weather, secondary shoots often regrow for a second smaller harvest from the same plant.
Watch for cabbage worms and aphids, the two most common bok choy pests. Floating row cover applied at planting eliminates most cabbage worm damage. Check the undersides of leaves weekly for aphid colonies and knock them off with a strong water spray.
Water in the morning so foliage dries before evening. Wet leaves overnight encourage fungal diseases like downy mildew, which is common on brassicas in humid conditions.
Grow baby bok choy varieties (like 'Toy Choy' or 'Joi Choi') in spring since their shorter days to maturity let you harvest before summer heat arrives. Save larger standard varieties for the longer, more reliable fall window.
Bok choy is an excellent candidate for cut-and-come-again harvesting when grown as a baby leaf — sow densely and harvest entire small plants at 4–5 inches. The bed can produce 2–3 successive cuts in cool weather before bolting.

Companion Planting

Bok choy and all brassicas require a 3-year rotation away from related crops — cabbage, broccoli, kale, cauliflower — to prevent clubroot disease. Radishes planted nearby are sometimes cited as a flea beetle deterrent, though results are variable. The planner helps you track brassica rotation across your beds.

FAQ

When should I plant bok choy?

Plant bok choy in early spring, 4–6 weeks before your last frost date, or in late summer (6–8 weeks before first fall frost) for a fall harvest. The fall window is often more productive because decreasing temperatures prevent bolting. In most of the US, this means August to September planting for October through November harvests.

Why is my bok choy bolting?

Bolting (sending up a flower stalk) is triggered by heat above 75°F, long days exceeding 13 hours, or a period of temperatures below 50°F followed by warm weather (vernalization). Once a plant bolts, leaves become bitter and the harvest window is over. To prevent bolting, plant during cool seasons, provide afternoon shade as temperatures warm, and harvest before the plant reaches full maturity.

Can I eat bok choy that has bolted?

The leaves are still edible after bolting, but become progressively more bitter and tough. The flower buds and flowers are actually quite tasty — tender and mild — and can be eaten similarly to broccoli florets. If your bok choy has bolted, harvest the flower shoots promptly before they fully open for the best flavor.

How do I prevent pests on bok choy?

The most effective prevention is physical exclusion with floating row cover applied immediately after planting. This keeps out cabbage moths (whose caterpillars are the dreaded cabbage worm), flea beetles, and aphids. Check plants every few days; if you find caterpillars, hand-pick them or apply Bt (Bacillus thuringiensis), a natural bacterial pesticide effective against caterpillars.

Is bok choy easy to grow?

Yes — bok choy is one of the fastest and easiest brassicas to grow when planted at the right time. Its short days to maturity (30–40 days for baby varieties) mean you see results quickly, and its tolerance for light frost makes timing less stressful than warm-season crops. The main challenge is timing plantings to avoid summer heat, which triggers bolting.