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When to Plant Savoy Cabbage in Broadwater County, MT

Broadwater County, Montana Zone 5a May

This month in Broadwater County, Montana

Welcome to May in Zone 5a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 20
Avg. first frost September 20
Soil temp (4") 30°F
Watering High
Pest pressure Low
Daylight 14.8 hrs
  1. Transplant savoy cabbage outside

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

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

    These tolerate cool soil, so you're not gambling by sowing now.

A few tasks this May that'll pay off in June
  • Starting indoors: savoy cabbage

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Savoy cabbage has crinkled, deeply veined leaves that form looser heads than regular cabbage. It has a milder, sweeter flavor and is more cold-tolerant.

Broadwater County, Montana is in USDA Zone 5a. The average last spring frost is May 20 and the first fall frost is September 20, giving you a growing season of approximately 123 days.

At an elevation of 7,806 feet, Broadwater County receives approximately 17.4 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Savoy Cabbage to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Savoy Cabbage successfully. Mulch heavily to conserve soil moisture.

Broadwater County, MT (Zone 5a) Short season
123 days
Last Spring Frost May 20
123 growing days
First Fall Frost September 20

Broadwater County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: Jul 19 – Sep 13
Recommended (50%) ✗ May not fit
Start indoors: Apr 15 Transplant: May 20 🍅 Harvest: Jul 29 – Sep 23
Safe Start (90%) ✗ May not fit
Start indoors: May 12 Transplant: Jun 16 🍅 Harvest: Aug 25 – Oct 20

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 Broadwater County

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

Soil pH

Your soil pH (6.6–8.1) overlaps with Savoy Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Savoy Cabbage.

How to Plant Savoy Cabbage

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 533 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Savoy Cabbage

Savoy Cabbage needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Savoy Cabbage Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 4.3" 2" 2.3" 🚿 Regular watering
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.7" 2.6" 🚿 Regular watering
Aug 4.3" 1.6" 2.7" 🚿 Regular watering
Sep 4.3" 1.5" 2.8" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

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

Savoy 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.

Savoy Cabbage needs ~1,102 GDD — county provides 1,506 GDD Excellent fit

Savoy Cabbage Planting Timeline — Broadwater County, MT

Savoy Cabbage Planting Calendar

Activity When Date Range
Start Indoors April 15 Apr 15 – Apr 29
Transplant Outdoors May 20 May 20 – Jun 3
Direct Sow May 6 May 6 – May 27
Harvest July 29 Jul 29 – Sep 23
Fall Sowing July 12 Jul 12 – Jul 26

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
July Fall Sowing Harvest
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

70–110 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

123 days in Broadwater County

Growing Tips for Savoy Cabbage in Broadwater County

Direct sow Savoy Cabbage outdoors after May 20 in Broadwater County when soil has warmed and frost danger has passed.

Your 123.0-day growing season in Broadwater County is tight for Savoy Cabbage (70.0-110.0 days to maturity). Start indoors and choose early-maturing varieties.

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

Broadwater County receives only 17" of rain annually. Savoy 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. Savoy cabbage is more forgiving of temperature fluctuations than smooth-leaved types. Excellent for stuffed cabbage rolls.

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 Savoy Cabbage in Broadwater County, MT?

Broadwater County is in Zone 5a with an average last frost of May 20. Plan your Savoy Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Broadwater County, MT?

Broadwater County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is May 20 and first fall frost is September 20.

🌱

Your Broadwater County Garden Planner — Free

A 24-page printable planner built for Broadwater County (Zone 5a). 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 Broadwater 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.