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When to Plant Cabbage in Sheridan County, MT

Sheridan County, Montana Zone 3b May

Top priorities for Sheridan County, Montana gardeners in May

A quick May briefing for Sheridan County, Montana gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 17
Avg. first frost September 18
Soil temp (4") 26°F
Watering High
Pest pressure Low
Daylight 15 hrs
  1. Move cabbage into the garden

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

  2. Direct-sow cabbage

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

June will be here before you know it — start on
  • 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.

Sheridan County, Montana is in USDA Zone 3b. The average last spring frost is May 17 and the first fall frost is September 18, giving you a growing season of approximately 124 days.

At an elevation of 8,209 feet, Sheridan County receives approximately 16.8 inches of rainfall annually with predominantly loam soil. Summer highs average 79°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.

Sheridan County, MT (Zone 3b) Short season
124 days
Last Spring Frost May 17
124 growing days
First Fall Frost September 18

Sheridan 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 (4 days to spare)
Start indoors: Apr 1 Transplant: May 13 🍅 Harvest: Jul 15 – Sep 9
Recommended (50%) ✓ Fits season (5 days to spare)
Start indoors: Apr 5 Transplant: May 17 🍅 Harvest: Jul 19 – Sep 13
Safe Start (90%) ✓ Fits season (0 days to spare)
Start indoors: Apr 22 Transplant: Jun 3 🍅 Harvest: Aug 5 – Sep 30

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 Sheridan 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 Sheridan County is excellent for Cabbage — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.6%). 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 124-day season

Sow every 6.9 weeks. Last sowing by Jun 10 to harvest before frost.

For a dedicated fall crop, sow by Jun 26.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 438 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 1.1" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 3.9" 2.1" 1.8" 💧 Light watering
Jun 3.9" 1.2" 2.7" 🚿 Regular watering
Jul 3.9" 1.5" 2.4" 🚿 Regular watering
Aug 3.9" 1.9" 2" 🚿 Regular watering
Sep 3.9" 1.2" 2.7" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 1.1" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Sheridan 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 ~740 GDD — county provides 1,147 GDD Excellent fit

Cabbage Planting Timeline — Sheridan County, MT

Cabbage Planting Calendar

Activity When Date Range
Start Indoors April 5 Apr 5 – Apr 19
Transplant Outdoors May 17 May 17 – May 31
Direct Sow May 10 May 10 – May 31
Harvest July 19 Jul 19 – Sep 13
Fall Sowing June 26 Jun 26 – Jul 10

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 3b

📆 Growing Season

124 days in Sheridan County

Growing Tips for Cabbage in Sheridan County

Direct sow Cabbage outdoors after May 17 in Sheridan 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.

Sheridan County receives only 17" 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 Sheridan County, MT?

Sheridan County is in Zone 3b with an average last frost of May 17. Plan your Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sheridan County, MT?

Sheridan County, Montana is in USDA Hardiness Zone 3b. The average last spring frost is May 17 and first fall frost is September 18.

🌱

Your Sheridan County Garden Planner — Free

A 24-page printable planner built for Sheridan County (Zone 3b). 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 Sheridan 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.