When to Plant Bok Choy in New Hampshire (2026 Guide)
Bok choy, a prized cool-season Asian brassica, is a staple for many New Hampshire gardeners. With its crisp white stalks and tender dark green leaves, this vegetable thrives in cooler temperatures, making it a perfect choice for spring and fall planting. However, timing your sowing is crucial as late frosts or hot weather can impact growth. In New Hampshire, the median last spring frost date varies, with areas like Concord experiencing this on May 11, while Salem sees it earlier on April 28.
Planting bok choy at the right time can lead to remarkable yields, with baby heads ready to harvest in as little as 30 days. To maximize your growing season, it's essential to understand your local frost dates and select the best windows for planting. New Hampshire gardens typically have a frost-free growing season that varies by region, being approximately 142 days in Zone 5b and around 164 days in Zone 6a.
As temperatures begin to drop in the fall, bok choy transitions into a more favorable growing phase. The cooler conditions paired with shorter daylight hours not only enhance flavor but can extend the harvest period. For those in areas like Derry or Dover, planning your planting around the median first fall frost on September 30 allows you to enjoy fresh bok choy even into late autumn.
Planting Schedule by USDA Zone in New Hampshire
| Zone | Indoor start | Transplant out | Direct sow | Harvest |
|---|---|---|---|---|
| Zone 5b | Start March 15 – March 30, ~6–8 weeks before May 11 | Transplant outdoors May 12 – May 25, after last frost | Direct sow April 15 – May 1, after last frost | Harvest June 15 – July 15, before heat triggers bolting |
| Zone 6a | Start March 1 – March 15, ~6–8 weeks before April 28 | Transplant outdoors April 29 – May 12, after last frost | Direct sow April 1 – April 15, after last frost | Harvest May 20 – June 20, before heat triggers bolting |
Bok Choy Planting Windows in New Hampshire
- Indoor start: In New Hampshire, start seeds indoors from March 1 to March 30 to prepare for optimal outdoor planting.
- Transplant outdoors: Transplant your seedlings outdoors from May 12 to May 25, after the last frost has passed.
- Harvest: Enjoy harvesting bok choy from June 15 to July 15, but be mindful to pick before heat causes bolting.
Common Mistakes Growing Bok Choy in New Hampshire
- One common mistake in New Hampshire is planting bok choy too late in the spring and risking bolting due to rising temperatures. If you're not careful, your plants may get too warm, resulting in a poor harvest.
- New Hampshire's unpredictable weather is another factor. Late spring snows can catch novice gardeners off guard, damaging newly sprouted plants or delaying planting schedules for bok choy.
- Many gardeners overlook the importance of soil moisture management. Humid conditions prevalent in summer can lead to fungal diseases like downy mildew. It’s critical to keep bok choy leaves dry to avoid such issues.
- A frequent error is sowing too deeply. Bok choy seeds should only be planted about half an inch deep, but beginners may inadvertently bury them too deeply in New Hampshire's often clay-heavy soils, preventing germination.
- Many New Hampshire gardeners also fail to recognize the necessity of crop rotation. Continual planting of bok choy or related brassicas in the same bed can lead to diseases like clubroot, which thrive in certain soil conditions.
Frequently Asked Questions
What if I'm in a cold pocket of New Hampshire?
If you're in a colder area, consider starting your bok choy indoors to get a head start. Transplant during the later half of May to allow the soil to warm up and minimize frost risk.
Can I still plant bok choy in May?
Yes, you can plant bok choy in May, especially in Zone 6a where the last frost is earlier. Just ensure you're putting them in after the last frost, which is around April 28, to avoid stunted growth.
Is it better to transplant or direct sow?
Transplanting allows for more controlled growth, especially if you start indoors. However, direct sowing can result in quickly established plants, depending on local conditions, so choose based on your gardening schedule.
Can bok choy handle light frost?
Bok choy is somewhat frost-tolerant and can handle light frosts, making it versatile for spring and fall. However, protect young plants from severe late frosts in New Hampshire to ensure a healthy harvest.
How do I know when to harvest my bok choy?
Harvest your bok choy heads when they reach about 6 to 8 inches tall and before they bolt. It's best to cut at soil level, which also encourages regrowth under the right conditions.
Keep Learning
City guides in New Hampshire
Other crops in New Hampshire
Typical fall sowing window for Bok Choy in New Hampshire: July 15 – August 5.