Growing Bok Choy in Zone 4B

Bok Choy is a crisp, fast-growing Asian green that thrives in cool weather. Baby bok choy varieties can be ready in just 30 days, making it ideal for spring and fall gaps in the garden.

Zone 4B has a short growing season — start seeds indoors when possible and use season-extending techniques like cold frames and row covers.

Top Growing Tips

• Sow indoors 4 weeks before last frost or direct sow in early spring
• Prefers soil temperatures between 45-75°F — bolts quickly in heat
• Space standard varieties 6-9 inches apart; baby types can be closer
• Harvest whole heads when compact, or cut outer leaves for partial harvest
• Fall sowing is often more successful — cooler temps prevent bolting

Companion Planting

Good companions: beets, onions, celery, aromatic herbs

Avoid planting near: strawberries, pole beans, tomatoes

Harvest Timeline

30-45 days (baby) to 50-70 days (full size)

About Zone 4B

USDA Hardiness Zone 4B has an average last spring frost around May 1 and first fall frost around Oct 1. All planting dates above are calculated from these frost dates. Your specific location may vary — check with your local extension office for the most accurate dates.