When to Plant Napa Cabbage in Belknap County, NH
May in the garden — Belknap County, New Hampshire
Here's what deserves your attention in Belknap County, New Hampshire this month. Everything below is tailored to Zone 5b and timed around your local frost dates.
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Move napa cabbage from tray to bed
Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.
Coming up in June — start thinking about
- Starting indoors: napa cabbage
- First harvests: napa cabbage
Napa cabbage forms tall, barrel-shaped heads with tender, crinkled leaves and a mild, slightly sweet flavor. It is the primary cabbage used for kimchi.
Belknap County, New Hampshire is in USDA Zone 5b. The average last spring frost is May 3 and the first fall frost is October 11, giving you a growing season of approximately 161 days.
At an elevation of 764 feet, Belknap County receives approximately 48.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Napa Cabbage during the growing season.
Belknap County Soil Profile
Soil Type
Silt Loam
Soil pH
4.8-6.8
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in Belknap County
How your county's soil matches Napa Cabbage's growing requirements.
Soil pH
Your soil pH (4.8–6.8) is more acidic than Napa Cabbage prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Belknap County is excellent for Napa Cabbage — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.5%). Annual compost additions will help Napa Cabbage.
How to Plant Napa Cabbage
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Napa Cabbage
Sow every 6.3 weeks. Last sowing by Jul 28 to harvest before frost.
For a dedicated fall crop, sow by Aug 02.
Plant Water Budget
Monthly Watering Guide for Napa Cabbage
Napa Cabbage needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Napa Cabbage Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3" | 0" | ❄️ Dormant |
| Feb | — | 3.4" | 0" | ❄️ Dormant |
| Mar | — | 4.4" | 0" | ❄️ Dormant |
| Apr | — | 3.9" | 0" | ❄️ Dormant |
| May | 6.5" | 3.9" | 2.6" | 💧 Light watering |
| Jun | 6.5" | 4.7" | 1.8" | 💧 Light watering |
| Jul | 6.5" | 4.9" | 1.6" | 💧 Light watering |
| Aug | 6.5" | 4.8" | 1.7" | 💧 Light watering |
| Sep | 6.5" | 3.8" | 2.7" | 💧 Light watering |
| Oct | 6.5" | 4.4" | 2.1" | 💧 Light watering |
| Nov | — | 3.8" | 0" | ❄️ Dormant |
| Dec | — | 3.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Belknap County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Napa Cabbage Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Napa Cabbage Planting Timeline — Belknap County, NH
Napa Cabbage Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 29 | Mar 29 – Apr 12 |
| Transplant Outdoors | May 3 | May 3 – May 17 |
| Direct Sow | April 19 | Apr 19 – May 10 |
| Harvest | June 28 | Jun 28 – Aug 2 |
| Fall Sowing | August 2 | Aug 2 – Aug 16 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1.5"/week · Only during dry spells
📅 Days to Maturity
55–75 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 5b
📆 Growing Season
161 days in Belknap County
Growing Tips for Napa Cabbage in Belknap County
Direct sow Napa Cabbage outdoors after May 03 in Belknap County when soil has warmed and frost danger has passed.
Common pests for Napa Cabbage in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Best grown as a fall crop. Direct sow in late summer, 60-70 days before first frost. Keep soil evenly moist. Bolt-resistant varieties are available for spring planting.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Napa Cabbage in Other Locations
Frequently Asked Questions
When should I plant Napa Cabbage in Belknap County, NH?
Belknap County is in Zone 5b with an average last frost of May 3. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.
What planting zone is Belknap County, NH?
Belknap County, New Hampshire is in USDA Hardiness Zone 5b. The average last spring frost is May 3 and first fall frost is October 11.
Your Belknap County Garden Planner — Free
A 24-page printable planner built for Belknap County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.