Can You Grow Bok Choy in Zone 4a?
Bok Choy grows well in Zone 4a
Bok choy grows reliably in your zone — it loves cool weather and handles light frosts.
📅 When to Plant in Zone 4a
Based on Zone 4a's average last frost of late April and first frost of early October — frost can arrive earlier or later in any given year, so check your local forecast before you transplant.
🌱 Growing Bok Choy in Zone 4a
Start indoors 4-6 weeks before last frost or direct sow in fall. Harvest outer leaves continuously or cut the whole head at 2 inches above soil for regrowth. Keep moist — dry conditions trigger bolting.
🗺️ USDA Plant Hardiness Zones
2023 USDA Plant Hardiness Zone Map — public domain. USDA Agricultural Research Service
USDA zones run 1a–13b (26 half-zones). Each full zone above covers both the a and b half-zones. Browse all US zones →
Technical climate details for Zone 4a
- USDA Zone
- 4a
- Last Frost
- late April
- First Frost
- early October
- Frost-Free Days
- 163
- Bok Choy Zone Range
- 4a – 9b
- Days to Harvest
- 45–60 days