Quick Growing Facts

When & Where to Grow Bok Choy ‘White Stem’

Bok choy loves cool weather and short days. It grows quickly and can bolt (flower) in long, hot days or when stressed. Plan sowings so most growth happens in spring and fall for tender, juicy stems and mild flavor.

• Spring: Sow outdoors 2–4 weeks before your average last frost date, once soil is workable and around 45–50°F (7–10°C).
• Fall: Sow 6–8 weeks before expected hard frost so plants can size up in cooling weather; fall crops often have the best texture and flavor.
• Mild / warm-winter climates: Grow bok choy through fall, winter, and early spring; avoid the hottest months or grow under shade cloth.
• Location: Garden beds, raised beds, and containers (at least 20–25 cm deep) in full sun to partial shade.

Soil Preparation

Bok choy is a fast-growing brassica that benefits from rich, moisture-retentive soil with good drainage. Well-prepared ground supports rapid growth, which keeps plants tender and reduces bolting.

• Loosen the top 8–10 in (20–25 cm) of soil and remove weeds, roots, and stones.
• Work in plenty of compost or well-rotted manure to boost fertility and moisture retention.
• Rake the surface into a fine, crumbly seedbed so the small seeds make good contact with the soil.
• Ensure good drainage; if soil is heavy clay, use raised beds or add additional organic matter and coarse material.
• Avoid very fresh, high-nitrogen manure right before sowing; too much nitrogen can make plants soft and more susceptible to pests.

Direct Sowing Bok Choy Outdoors

Bok choy can be direct sown or transplanted. Direct sowing is excellent for baby bok choy, salad mixes, and quick crops in cool weather.

1. Timing: Sow in early spring and again in late summer to fall when soil is cool to mild.
2. Row method: Make shallow furrows 12–18 in (30–45 cm) apart.
3. Sowing depth: Sow seeds about 1/4 in (6 mm) deep; they should be just lightly covered.
4. Seed spacing: Sow about 1 in (2–3 cm) apart in the row; you will thin later for final spacing.
5. Broadcast for baby leaves: For salad greens, scatter seeds thinly over the bed and lightly rake or tamp into the surface.
6. Water: Water gently with a fine spray and keep the top layer of soil consistently moist until seedlings emerge.

Starting Bok Choy Indoors

Starting ‘White Stem’ bok choy indoors gives you a head start in spring and allows you to set out strong seedlings that mature quickly before hot weather. It also helps create uniform beds of full-size plants.

• Sow 3–4 weeks before your last expected frost date.
• Use cell trays or small pots with a fine, well-draining seed-starting mix.
• Sow 2–3 seeds per cell at about 1/4 in (6 mm) deep and thin to one strong seedling.
• Keep at 60–75°F (15–24°C) with even moisture and bright light to prevent leggy growth.
• Harden off seedlings for about a week, then transplant outdoors, spacing 6–10 in (15–25 cm) apart, depending on desired plant size.

Thinning, Spacing & Transplanting

Proper spacing allows bok choy to form nice rosettes or heads and reduces competition and disease. Use thinnings as tender microgreen-style harvests so nothing goes to waste.

• Thin direct-sown seedlings when they are 2–3 in (5–8 cm) tall.
• For baby bok choy, thin to about 3–4 in (8–10 cm) between plants.
• For medium to full-size plants, thin or transplant to 6–10 in (15–25 cm) between plants in rows 12–18 in (30–45 cm) apart.
• Snip extra seedlings at the soil line to avoid disturbing roots, or gently transplant them if soil is loose and moist.
• Transplant on a cool, cloudy day or in the evening and water in well.

Succession Sowing for Continuous Harvest

Because bok choy grows quickly and prefers cool weather, succession sowing ensures a steady supply of young, tender plants before heat or bolting become a problem.

• Sow a new small patch every 2–3 weeks in spring and again in late summer to early fall.
• In hot climates, avoid sowing in the hottest months or grow under shade cloth with extra water.
• For fall crops, plan sowings so plants are well established before first hard frost; under row cover they may continue producing into early winter.

Watering & Feeding

Bok choy has shallow roots and grows quickly, so it needs steady moisture and moderate fertility. Stress from drought or inconsistent watering encourages bolting and tough stalks.

• Watering: Keep soil evenly moist but not waterlogged. Aim for consistent moisture, especially during warm or windy periods.
• Mulch: A light mulch of compost or straw helps retain moisture, suppress weeds, and keep roots cool.
• Feeding: In addition to compost at planting, feed with a balanced organic fertilizer or liquid feed (compost tea, fish emulsion) once or twice during the growing period, especially in poor soils or containers.

Pests & Diseases

Bok choy is a brassica and shares pests with cabbage, kale, and mustard greens. Fast growth, row covers, and good garden hygiene are the best tools for keeping it healthy.

• Flea beetles: Tiny beetles that chew many small holes in leaves. Use floating row covers, keep soil moist, and promote quick growth so plants outgrow damage.
• Cabbage worms & caterpillars: Look for green caterpillars and droppings on leaves; hand-pick or use organic controls like Bacillus thuringiensis (Bt) if needed.
• Aphids: Rinse off with water or use insecticidal soap if colonies build up on new growth.
• Slugs & snails: Common in damp conditions; use traps, barriers, and hand-picking, and avoid thick mulch directly at the plant base.
• Fungal diseases: Downy mildew and leaf spots are more likely in cool, wet, crowded plantings. Provide good spacing, avoid overhead watering late in the day, and rotate crops.
• Bolting: Sudden temperature swings, stress, or lengthening days can cause early flowering. Grow mainly in cool seasons and keep plants consistently watered and fed.

Harvesting Bok Choy ‘White Stem’

Baby Leaves & Mini Heads

• Begin harvesting baby leaves about 20–30 days after sowing, when leaves are 3–4 in (7–10 cm) long.
• Snip outer leaves as needed or cut entire mini heads at the base when plants are 3–6 in (8–15 cm) tall.
• Baby bok choy is tender and ideal for stir-fries, quick sautés, and soups.

Medium & Full-Size Plants

• For medium to full-size plants, harvest around 35–50 days after sowing, once rosettes or heads are firm and well-formed.
• You can harvest whole plants by cutting at the base just above the soil line, or pick outer leaves and stalks as a cut-and-come-again crop.
• Harvest in the cool of the morning for the best texture and sweetness.
• If plants begin to bolt, harvest promptly; bolting plants can still be eaten, but stalks and leaves become stronger in flavor and texture.

Storing & Using Bok Choy

• Rinse plants in cool water to remove soil, especially at the base of the stalks; separate stalks if needed.
• Dry gently and store in a breathable or lightly sealed container/bag in the refrigerator.
• Use within about 5–7 days for best quality and crunch.
• Use baby bok choy whole or halved in stir-fries, braises, soups, noodle dishes, and quick sautés.
• White stems are juicy and crisp; leaves cook quickly. Add stems first and leaves last when cooking.

Saving Seed from Bok Choy

Bok choy is a biennial that usually flowers in its second season after cold exposure, but it can bolt in its first year in response to stress or long days. It can cross with other Brassica rapa types (such as turnips and some other Asian greens), so isolation is needed for pure seed.

• Select healthy, true-to-type plants and allow them to bolt and flower.
• Plants will send up tall stalks with yellow flowers, followed by slender seed pods.
• When pods turn tan-brown and feel dry, cut seed stalks into a paper bag or over a tray before they shatter.
• Dry thoroughly, then crush pods gently to release seeds and winnow out chaff.
• Store seeds in a labeled, airtight container in a cool, dark, dry place. Under good conditions, bok choy seeds remain viable for several years.

Tips for Success

• Treat bok choy as a cool-season crop: focus on spring and fall, and protect or shade plants in hot weather.
• Use row covers early in spring to speed growth, protect from flea beetles, and reduce temperature swings that trigger bolting.
• Make small, frequent sowings instead of one large planting to keep quality high and harvests continuous.
• Experiment with plant spacing: closer spacing for mini bok choy, wider spacing for large, full-size plants.
• Harvest regularly, using both leaves and stems, to keep plants productive and enjoy the best flavor and texture.

Note: Growing conditions and timing vary by region. Adjust sowing dates, watering, and heat or frost protection to match your local climate and weather patterns.