Bok Choy
Brassica rapa subsp. chinensis
Family: Brassicaceae
Bok choy is a fast-growing Chinese cabbage with crisp white stems and tender dark green leaves. Essential in Asian cooking, it grows quickly in cool weather and can be harvested at any size from baby to full-grown.
Days to Harvest
30-60 days
Sun Needs
Full Sun to Part Shade (4-6 hours)
moderate
Germination Temp
65°F optimal
Start Indoors
4 weeks before last frost
Germination
4-10 days
Seed Depth
1/4 inch
Light to Germinate
No
💡 Tip: Direct sow for best results. Grows fast and bolts quickly in heat.
Soil Type
Rich, well-draining soil
pH Range
6 - 7.5
Spacing
6-12 inches depending on harvest size
⚠️ Avoid planting near:
History
Bok choy stands as one of humanity's oldest cultivated vegetables, with archaeological evidence suggesting cultivation in the Yangtze River delta region of China dating back over 5,000 years. The Cantonese name "baak choi" translates to "white vegetable," referring to its distinctive pale stems, while Mandarin speakers call it "qingcai" (green vegetable) or "xiaobai cai" (small white vegetable). Throughout Chinese history, bok choy held a place of honor as a symbol of good fortune—its pronunciation similar to words meaning "a hundred fortunes." The vegetable became integral to Chinese medicinal food traditions, prescribed for clearing internal heat and promoting digestion. Different regional varieties developed across China, from the green-stemmed Shanghai varieties to the classic white-stemmed Cantonese types. Bok choy traveled along ancient trade routes to Korea, Japan, and Southeast Asia, where local variations emerged. Western discovery came through Chinese immigrant communities in the 19th century, though widespread cultivation outside Asia only began in the 1970s as interest in Asian cuisine exploded. Today bok choy ranks among the most popular Asian vegetables worldwide, prized for its quick growth, versatility in cooking, and exceptional nutritional density.
Nutritional Benefits
- ✓Extremely high in Vitamin A
- ✓Excellent source of Vitamin C
- ✓Rich in Vitamin K
Optimal Growing Temp
55°F - 70°F
Bok choy prefers cool conditions between 55-70°F for best growth. It tolerates light frosts well but bolts quickly when temperatures exceed 75°F. Fast maturity (30-50 days) makes it easier to time for cool weather.
Survival Range
35°F - 80°F
Can survive these temperatures
Frost Note: Bok choy is moderately cold-hardy, tolerating light frosts down to 25°F. Mature plants handle cold better than seedlings. Some varieties are bred specifically for cold tolerance and can overwinter in mild climates.
Best USDA Zones
Humidity
50-70%
Tolerates various humidity levels. In high humidity, ensure good air circulation to prevent fungal diseases. Bok choy handles humidity better than heading cabbages due to its open rosette structure.
Height
8-15 inches
Spread
8-12 inches
Growth Habit
upright
Germination
3-7 days
Seeds germinate quickly at 50-80°F, with optimal germination around 65°F. Bok choy is one of the fastest-germinating brassicas.
Seedling Stage
Duration: 2-3 weeks
True leaves: First true leaves appear 5-7 days after sprouting with smooth, spoon-shaped form
Transplant ready: Ready to transplant when 2-3 inches tall with 3-4 true leaves, or direct sow for best results.
Vegetative Growth
Duration: 3-5 weeks
Rapid growth of leaves and white stalks forming the characteristic rosette. Baby bok choy can be harvested at 3-4 weeks; full-size at 6-8 weeks.
Flowering
Timing: Bolts rapidly in heat or with long days
Duration: Once bolting starts, plants become bitter within days
Yellow flowers appear on a central stalk. Bolting is triggered by heat, long days, or cold exposure followed by warmth.
Harvest Maturity
Timing: 30-50 days for baby bok choy, 45-60 days for full-size
- Compact rosette of thick white stalks and dark green leaves
- Stalks are crisp and plump
- Center has not started to elongate (sign of bolting)
- Baby varieties are 4-6 inches, full-size 8-12 inches
Per Plant
0.25-0.5 lb per plant for baby, 0.5-1 lb for full-size
Per Square Foot
1-2 lbs per square foot with close spacing
Harvest Frequency
Cut whole heads or harvest outer leaves over several weeks
Factors Affecting Yield
- •Fast maturity allows multiple harvests per season
- •Cool temperatures produce best quality and flavor
- •Consistent moisture prevents bitter flavor and promotes tender stalks
- •Harvest before any sign of bolting for best taste
- •Baby varieties mature faster and are ideal for limited space
Seedling Stage
Keep consistently moist—bok choy needs steady moisture from germination
Established Plants
1 inch per week, maintaining even soil moisture
During Fruiting
Consistent moisture throughout—water stress causes bolting and bitter flavor
Preferred Method
Water at soil level to avoid wetting leaves, which can cause fungal issues. Drip irrigation or soaker hoses work well.
⚠️ Critical Watering Periods
- • Entire growing period—bok choy is fast but unforgiving of stress
Pro Tips
- Consistent moisture is essential for tender, mild bok choy
- Mulch to maintain even soil moisture
- Water stress triggers bolting and bitterness
- Morning watering reduces disease risk
Feeding Schedule
At Planting
Balanced fertilizer or compost worked into soil
Once at planting
Mid-Growth
Side-dress with nitrogen-rich fertilizer
Once, 2-3 weeks after planting
Organic Options
Work compost into soil before planting. Apply fish emulsion every 2-3 weeks for quick-growing leafy crops.
Minimum Size
2 gallon minimum for baby varieties
Recommended Size
5 gallon for full-size, or multiple baby plants
Depth Required
At least 6-8 inches deep—bok choy has shallow roots
Best Varieties for Containers
Container Tips
- Excellent container vegetable due to small size and fast growth
- Baby bok choy varieties are perfect for small containers and windowsills
- Space baby varieties 4-6 inches apart, full-size 8-10 inches
- Use quality potting mix and keep consistently moist
- Position in partial shade during warm weather to delay bolting
- Harvest leaves frequently to encourage continued production
Why Prune
When
Begin harvesting outer leaves when plants are 4-6 inches tall
How Often
Harvest outer leaves every few days for extended harvest
Technique
Harvest outer leaves at the base, leaving the center to continue growing. Or harvest entire heads at once.
Remove
- ✗ Outer mature leaves for harvest
- ✗ Any yellowed or damaged leaves
Keep
- ✓ Center growing point for continued production
- ✓ At least 3-4 inner leaves when harvesting
Plant Every
2 weeks
Sowings/Season
4-6 plantings for continuous harvest
Duration
Spring: 4-6 weeks before last frost through 4 weeks after. Fall: 10-12 weeks before first frost through first frost
Tips
- Fast maturity makes bok choy ideal for succession planting
- Sow every 2 weeks for continuous supply
- Skip succession during hottest summer weeks
- Both spring and fall successions work well
- Fall plantings often produce best quality due to cooling temperatures
