Intermediate Bok Choy Growing: Succession Planting & Variety Selection

Intermediate Bok Choy Growing: Succession Planting & Variety Selection

Ready to move beyond basic bok choy growing? This intermediate guide explores the diversity of Chinese cabbages, teaches you to plan succession plantings for year-round harvest, and provides strategies for managing the most common challenges. Whether you're growing for a farmers market or a well-stocked home kitchen, these techniques will elevate your bok choy production.

The World of Chinese Cabbages

Understanding the Brassica rapa Complex

Bok choy belongs to the species Brassica rapa, which includes many Asian vegetables. Understanding these relationships helps with variety selection and cross-pollination management.

Key Brassica rapa Groups:

Comprehensive Variety Guide

Standard Bok Choy (White Stem):

Shanghai Type (Green Stem):

Baby Bok Choy:

Specialty Types:

Selecting Varieties for Your Climate

Hot/Warm Climates (Zones 8-11):

• Focus on bolt-resistant varieties: Hanakan, Joi Choi
• Grow primarily in fall, winter, and early spring
• Try heat-tolerant Shanghai types

Cool/Temperate Climates (Zones 4-7):

• Widest variety selection possible
• Spring and fall are primary seasons
• Can extend into summer with shade cloth

Year-Round Growing:

• Rotate between seasonal varieties
• Use protective structures for extreme weather
• Succession plant every 2-3 weeks

Succession Planting Mastery

Planning Your Planting Schedule

Basic Succession Principle: Plant new seeds or transplants every 2-3 weeks for continuous harvest.

Spring-Summer Schedule (Zones 5-7):

Fall-Winter Schedule (Zones 8-10):

Calculating Planting Quantities

For Family of 4:

• Weekly consumption: 4-6 heads
• Days to maturity: ~45 (average)
• Germination/transplant buffer: 7 days
• Recommended: Plant 8-10 plants every 2 weeks

For Market Production:

• Track sales to determine weekly demand
• Plant 25-50% more than expected need
• Account for culls and pest damage
• Consider cut-and-come-again harvesting for baby greens

Advanced Soil and Nutrient Management

Optimal Soil Conditions

Soil Test Targets:

Fertilization Program

Pre-Plant:

• Incorporate 2-4 inches of compost
• Apply balanced organic fertilizer (4-4-4) at 4 lbs/100 sq ft
• Add calcium source if needed (gypsum or lime)

Growing Season:

Micronutrient Management

Brassicas have high micronutrient demands:

• Boron: Apply 1-2 lbs borax per acre if deficient (hollow stem prevention)
• Molybdenum: Important in acidic soils, foliar spray 1-2 ppm
• Calcium: Prevents tip burn, maintain soil pH above 6.0

Integrated Pest Management

Pest Identification and Life Cycles

Diamondback Moth (Plutella xylostella): Most significant pest globally for brassicas.

Monitoring: Scout twice weekly. Action threshold: 5 larvae per 10 plants.

Flea Beetles (Phyllotreta spp.):

Control Strategies:

Disease Prevention

Clubroot (Plasmodiophora brassicae): Soil-borne disease causing root galls and plant stunting.

Prevention:

• Maintain soil pH 7.0-7.2 (liming acidic soils)
• 7+ year rotation away from brassicas
• Clean equipment between fields
• Resistant varieties when available

Alternaria Leaf Spot (Alternaria brassicicola):

Prevention Strategies:

• Use certified disease-free seed
• Hot water seed treatment (122°F for 25 minutes)
• Improve air circulation (proper spacing)
• Avoid overhead irrigation
• Remove crop debris after harvest

Downy Mildew (Hyaloperonospora parasitica):

Management:

• Morning irrigation (leaves dry by evening)
• Space plants for air movement
• Copper fungicides (organic) preventively
• Remove and destroy affected plants

Season Extension Techniques

Row Covers and Low Tunnels

Row Cover Types:

Low Tunnel Construction:

1. Install wire hoops (9-gauge wire, 4-5 ft wide)
2. Space hoops every 4-5 feet
3. Cover with row cover or greenhouse plastic
4. Secure edges with sandbags or soil

Cold Frame Growing

Cold Frame Planting Schedule:

• Plant in late September/early October
• Use cold-hardy varieties (Tatsoi, Yukina Savoy)
• Harvest through December-February
• Ventilate when temperatures exceed 45°F

Winter Care:

• Add extra insulation (straw bales, blankets) during extreme cold
• Water sparingly when plants are dormant
• Harvest outer leaves only, leaving plant intact

Shade Cloth for Summer

When to Use:

• Temperatures consistently above 75°F
• To prevent bolting in spring plantings
• During heat waves

Specifications:

• 30-40% shade for bok choy
• Install 6-12 inches above plants
• Allow for air circulation

Harvest and Post-Harvest Handling

Optimal Harvest Timing

Field Handling

1. Harvest in early morning (highest turgor)
2. Cut cleanly at soil level
3. Remove damaged outer leaves
4. Place in shade immediately
5. Move to cold storage within 1 hour

Post-Harvest Storage

Optimal Conditions:

• Temperature: 32-35°F (0-2°C)
• Relative humidity: 95-100%
• Storage life: 2-3 weeks (standard), 1-2 weeks (baby)

Pre-Cooling:

• Hydrocooling: Immerse in 32°F water for 15-20 minutes
• Forced-air cooling: 1-2 hours to target temperature
• Vacuum cooling: For packed product

Troubleshooting Intermediate Challenges

Problem: Uneven plant sizes at harvest

• Cause: Variable germination, spacing, or transplant stress
• Solution: Pre-germinate seeds, transplant at uniform size, consistent spacing

Problem: Hollow or split stalks

• Cause: Boron deficiency, rapid growth, or water stress
• Solution: Soil test for boron, consistent irrigation

Problem: Yellow lower leaves before harvest

• Cause: Normal aging, nitrogen deficiency, or root problems
• Solution: Side-dress nitrogen if pale, check for root diseases

Problem: Early bolting in spring

• Cause: Transplants stressed, temperature fluctuations
• Solution: Harden off gradually, use bolt-resistant varieties, avoid cold shocks

Next Steps: Advancing Your Skills

Ready for more advanced techniques? Consider:

1. Growing for commercial markets
2. Implementing precision irrigation
3. Hydroponic or aquaponic bok choy production
4. Breeding and seed saving

With these intermediate techniques, you'll achieve consistent, high-quality bok choy harvests throughout the growing season.