When to Plant Napa Cabbage in Billings County, ND
This month in Billings County, North Dakota
Welcome to May in Zone 4a. These are the moves that will have the biggest impact on your growing season.
-
Move napa cabbage into the garden
Your last frost (May 19) has passed. These warm-season crops can handle outdoor soil now.
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Scatter napa cabbage into prepared beds
Your soil is 55°F — warm enough for these to germinate without babying.
A few tasks this May that'll pay off in June
- Starting indoors: napa cabbage
- Fall sowing: 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.
Billings County, North Dakota is in USDA Zone 4a. The average last spring frost is May 19 and the first fall frost is September 21, giving you a growing season of approximately 125 days.
At an elevation of 894 feet, Billings County receives approximately 26.2 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Napa Cabbage to ensure they mature before fall.
Billings County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.4
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 Billings County
How your county's soil matches Napa Cabbage's growing requirements.
Soil pH
Your soil pH (6.5–7.4) is within Napa Cabbage's preferred range (6.0–7.5).
Soil Texture
The loam soil in Billings County is excellent for Napa Cabbage — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (4.0%). Annual compost additions will help Napa Cabbage.
How to Plant Napa Cabbage
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Napa Cabbage
Sow every 6.3 weeks. Last sowing by Jul 08 to harvest before frost.
For a dedicated fall crop, sow by Jun 29.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
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 | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | — | 3" | 0" | ❄️ Dormant |
| May | 6.5" | 3.3" | 3.2" | 💧 Light watering |
| Jun | 6.5" | 1.6" | 4.9" | 🚿 Regular watering |
| Jul | 6.5" | 2.3" | 4.2" | 🚿 Regular watering |
| Aug | 6.5" | 2.9" | 3.6" | 🚿 Regular watering |
| Sep | 6.5" | 2.4" | 4.1" | 🚿 Regular watering |
| Oct | — | 2" | 0" | ❄️ Dormant |
| Nov | — | 1.7" | 0" | ❄️ Dormant |
| Dec | — | 1.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Billings 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 — Billings County, ND
Napa Cabbage Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 7 | Apr 7 – Apr 21 |
| Transplant Outdoors | May 19 | May 19 – Jun 2 |
| Direct Sow | May 12 | May 12 – Jun 2 |
| Harvest | July 14 | Jul 14 – Aug 18 |
| Fall Sowing | June 29 | Jun 29 – Jul 13 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow Fall Sowing |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1.5"/week · 2-3 times/week
📅 Days to Maturity
55–75 days
🧪 Soil pH
Needs 6–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 4a
📆 Growing Season
125 days in Billings County
Growing Tips for Napa Cabbage in Billings County
Direct sow Napa Cabbage outdoors after May 19 in Billings 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 Billings County, ND?
Billings County is in Zone 4a with an average last frost of May 19. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.
What planting zone is Billings County, ND?
Billings County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 19 and first fall frost is September 21.
Your Billings County Garden Planner — Free
A 24-page printable planner built for Billings County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.