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When to Plant Napa Cabbage in Bethel Census Area, AK

Bethel Census Area, Alaska Zone 4a May

Your May planting checklist for Bethel Census Area, Alaska

Here's what deserves your attention in Bethel Census Area, Alaska this month. Everything below is tailored to Zone 4a and timed around your local frost dates.

Avg. last frost May 22
Avg. first frost September 21
Soil temp (4") 45°F
Watering High
Pest pressure Low
Daylight 17 hrs
  1. Move napa cabbage from tray to bed

    Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.

  2. Plant napa cabbage from seed, right in the garden

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

Looking ahead to June
  • Fall sowing: napa cabbage

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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.

Bethel Census Area, Alaska is in USDA Zone 4a. The average last spring frost is May 22 and the first fall frost is September 21, giving you a growing season of approximately 122 days.

At an elevation of 1,369 feet, Bethel Census Area receives approximately 50.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 70°F, so choose short-season varieties of Napa Cabbage to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Napa Cabbage root diseases.

Bethel Census Area, AK (Zone 4a) Short season
122 days
Last Spring Frost May 22
122 growing days
First Fall Frost September 21

Bethel Census Area Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (31 days to spare)
Start indoors: Apr 4 Transplant: May 16 🍅 Harvest: Jul 11 – Aug 15
Recommended (50%) ✓ Fits season (31 days to spare)
Start indoors: Apr 10 Transplant: May 22 🍅 Harvest: Jul 17 – Aug 21
Safe Start (90%) ✓ Fits season (26 days to spare)
Start indoors: Apr 22 Transplant: Jun 3 🍅 Harvest: Jul 29 – Sep 2

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 Bethel Census Area

How your county's soil matches Napa Cabbage's growing requirements.

Soil pH

Your soil pH (5.2–6.3) is more acidic than Napa Cabbage prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Bethel Census Area is excellent for Napa Cabbage — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Napa Cabbage.

Organic Matter

Organic matter is excellent (5.8%) — Napa Cabbage will thrive.

How to Plant Napa Cabbage

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Napa Cabbage

2
successive plantings in your 122-day season

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

Plant needs
1.5″/week
Rainfall provides
1.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 2.6" 0" ❄️ Dormant
Feb 2" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 1.4" 0" ❄️ Dormant
May 6.5" 1.8" 4.7" 🚿 Regular watering
Jun 6.5" 4" 2.5" 💧 Light watering
Jul 6.5" 6.3" 0.2" 💧 Light watering
Aug 6.5" 7.6" 0" ✅ Rainfall sufficient
Sep 6.5" 9.4" 0" ✅ Rainfall sufficient
Oct 6.7" 0" ❄️ Dormant
Nov 4.1" 0" ❄️ Dormant
Dec 2.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Bethel Census Area). 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 needs ~162 GDD — county provides 305 GDD Excellent fit

Napa Cabbage Planting Timeline — Bethel Census Area, AK

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors April 10 Apr 10 – Apr 24
Transplant Outdoors May 22 May 22 – Jun 5
Direct Sow May 15 May 15 – Jun 5
Harvest July 17 Jul 17 – Aug 21
Fall Sowing June 29 Jun 29 – Jul 13

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
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 · Natural rainfall sufficient

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 4a

📆 Growing Season

122 days in Bethel Census Area

Growing Tips for Napa Cabbage in Bethel Census Area

Direct sow Napa Cabbage outdoors after May 22 in Bethel Census Area 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

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Napa Cabbage in Bethel Census Area, AK?

Bethel Census Area is in Zone 4a with an average last frost of May 22. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bethel Census Area, AK?

Bethel Census Area, Alaska is in USDA Hardiness Zone 4a. The average last spring frost is May 22 and first fall frost is September 21.

🌱

Your Bethel Census Area Garden Planner — Free

A 24-page printable planner built for Bethel Census Area (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Bethel Census Area, AK. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.