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When to Plant Cabbage in Garfield County, MT

Garfield County, Montana Zone 4b May

What to do in May

Welcome to May in Zone 4b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 16
Avg. first frost September 21
Soil temp (4") 28°F
Watering High
Pest pressure Low
Daylight 14.9 hrs
  1. Get cabbage in the ground

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

  2. Plant 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
  • Starting indoors: cabbage
  • Fall sowing: cabbage

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Cabbage is a versatile cool-season crop that forms dense, leafy heads in green, red, or savoy varieties. It is a staple for coleslaw, sauerkraut, and many global cuisines.

Garfield County, Montana is in USDA Zone 4b. The average last spring frost is May 16 and the first fall frost is September 21, giving you a growing season of approximately 128 days.

At an elevation of 8,464 feet, Garfield County receives approximately 18.8 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Cabbage to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Cabbage successfully. Mulch heavily to conserve soil moisture.

Garfield County, MT (Zone 4b) Short season
128 days
Last Spring Frost May 16
128 growing days
First Fall Frost September 21

Garfield County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Start indoors: Mar 29 Transplant: May 10 🍅 Harvest: Jul 12 – Sep 6
Recommended (50%) ✓ Fits season (9 days to spare)
Start indoors: Apr 4 Transplant: May 16 🍅 Harvest: Jul 18 – Sep 12
Safe Start (90%) ✓ Fits season (15 days to spare)
Start indoors: Apr 18 Transplant: May 30 🍅 Harvest: Aug 1 – Sep 26

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 Garfield County

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

Soil pH

Your soil pH (6.3–7.9) overlaps with Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Cabbage.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Cabbage.

How to Plant 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 Cabbage

2
successive plantings in your 128-day season

Sow every 6.9 weeks. Last sowing by Jun 13 to harvest before frost.

For a dedicated fall crop, sow by Jun 29.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.6″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 756 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Cabbage

Cabbage needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Cabbage Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 3.9" 2.3" 1.6" 💧 Light watering
Jun 3.9" 1.4" 2.5" 🚿 Regular watering
Jul 3.9" 1.5" 2.4" 🚿 Regular watering
Aug 3.9" 2" 1.9" 💧 Light watering
Sep 3.9" 1.8" 2.1" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

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

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.

Cabbage needs ~860 GDD — county provides 1,376 GDD Excellent fit

Cabbage Planting Timeline — Garfield County, MT

Cabbage Planting Calendar

Activity When Date Range
Start Indoors April 4 Apr 4 – Apr 18
Transplant Outdoors May 16 May 16 – May 30
Direct Sow May 9 May 9 – May 30
Harvest July 18 Jul 18 – Sep 12
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 Fall Sowing
July Fall Sowing Harvest
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · 1-2 times/week

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

128 days in Garfield County

Growing Tips for Cabbage in Garfield County

Direct sow Cabbage outdoors after May 16 in Garfield County when soil has warmed and frost danger has passed.

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

Garfield County receives only 19" of rain annually. Cabbage needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 4-6 weeks before last frost. Space plants 18-24 inches apart. Keep soil evenly moist to prevent heads from splitting.

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 Cabbage in Garfield County, MT?

Garfield County is in Zone 4b with an average last frost of May 16. Plan your Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Garfield County, MT?

Garfield County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 16 and first fall frost is September 21.

🌱

Your Garfield County Garden Planner — Free

A 24-page printable planner built for Garfield 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 Garfield County, MT. 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.