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When to Plant Chinese Cabbage in Carbon County, MT

Carbon County, Montana Zone 4b April

Top priorities for Carbon County, Montana gardeners in April

April is a pivotal month for Carbon County, Montana gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 13
Avg. first frost September 28
Soil temp (4") 25°F
Watering High
Pest pressure Low
Daylight 13.3 hrs
Looking ahead to May
  • Transplants going out: chinese cabbage
  • Direct-sowing: chinese cabbage

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Chinese cabbage (Napa cabbage) forms elongated, barrel-shaped heads with tender, mild-flavored leaves. It is a staple in Asian cooking, particularly for kimchi.

Carbon County, Montana is in USDA Zone 4b. The average last spring frost is May 13 and the first fall frost is September 28, giving you a growing season of approximately 138 days.

At an elevation of 5,849 feet, Carbon County receives approximately 23.3 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Chinese Cabbage to ensure they mature before fall.

Carbon County, MT (Zone 4b) Short season
138 days
Last Spring Frost May 13
138 growing days
First Fall Frost September 28
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Carbon County Soil Profile

Soil Type

Loam

Soil pH

6.8-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (52 days to spare)
Start indoors: Mar 26 Transplant: May 7 🍅 Harvest: Jul 2 – Jul 30
Recommended (50%) ✓ Fits season (54 days to spare)
Start indoors: Apr 1 Transplant: May 13 🍅 Harvest: Jul 8 – Aug 5
Safe Start (90%) ✓ Fits season (42 days to spare)
Start indoors: Apr 29 Transplant: Jun 10 🍅 Harvest: Aug 5 – 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 Carbon County

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

Soil pH

Your soil pH (6.8–8.1) overlaps with Chinese Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Carbon County is excellent for Chinese Cabbage — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Chinese Cabbage.

How to Plant Chinese 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 Chinese Cabbage

3
successive plantings in your 138-day season

Sow every 5.7 weeks. Last sowing by Jul 20 to harvest before frost.

For a dedicated fall crop, sow by Jul 06.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.7″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 1,166 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Chinese Cabbage

Chinese 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 Chinese Cabbage Needs Rainfall You Supplement Action
Jan 1.9" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 2.6" 0" ❄️ Dormant
May 6.5" 2.4" 4.1" 🚿 Regular watering
Jun 6.5" 1.9" 4.6" 🚿 Regular watering
Jul 6.5" 2" 4.5" 🚿 Regular watering
Aug 6.5" 2.2" 4.3" 🚿 Regular watering
Sep 6.5" 1.8" 4.7" 🚿 Regular watering
Oct 2.2" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Carbon County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Chinese 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.

Chinese Cabbage needs ~735 GDD — county provides 1,690 GDD Excellent fit

Chinese Cabbage Planting Timeline — Carbon County, MT

Chinese Cabbage Planting Calendar

Activity When Date Range
Start Indoors April 1 Apr 1 – Apr 15
Transplant Outdoors May 13 May 13 – May 27
Direct Sow May 6 May 6 – May 27
Harvest July 8 Jul 8 – Aug 5
Fall Sowing July 6 Jul 6 – Jul 20

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
July Fall Sowing Harvest
August Harvest
September
October
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

138 days in Carbon County

Growing Tips for Chinese Cabbage in Carbon County

Direct sow Chinese Cabbage outdoors after May 13 in Carbon County when soil has warmed and frost danger has passed.

Common pests for Chinese Cabbage in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

Carbon County receives only 23" of rain annually. Chinese Cabbage needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Best grown as a fall crop to avoid bolting. Start seeds indoors or direct sow in late summer. Keep soil consistently moist and provide shade in warm weather.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Chinese Cabbage in Carbon County, MT?

Carbon County is in Zone 4b with an average last frost of May 13. Plan your Chinese Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Carbon County, MT?

Carbon County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 13 and first fall frost is September 28.

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Your Carbon County Garden Planner — Free

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

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

Sources & credits

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