When to Plant Savoy Cabbage in Petroleum County, MT
May to-do list for Petroleum County, Montana
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Petroleum County, Montana.
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Harden off and plant savoy cabbage
Your last frost (May 18) has passed. These warm-season crops can handle outdoor soil now.
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Outdoor sowing time: savoy cabbage
Mark the row. Birds and stray feet both have opinions about unmarked beds.
Get ahead of June
- Starting indoors: savoy cabbage
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.
Petroleum County, Montana is in USDA Zone 4b. The average last spring frost is May 18 and the first fall frost is September 24, giving you a growing season of approximately 129 days.
At an elevation of 8,358 feet, Petroleum County receives approximately 13.7 inches of rainfall annually with predominantly loam soil. Summer highs average 81°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.
Petroleum County Soil Profile
Soil Type
Loam
Soil pH
6.8-8.2
Drainage
Well Drained
Plant Planting Risk Windows
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 Petroleum County
How your county's soil matches Savoy Cabbage's growing requirements.
Soil pH
Your soil pH (6.8–8.2) overlaps with Savoy Cabbage's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Petroleum County is excellent for Savoy Cabbage — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Savoy Cabbage.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Savoy Cabbage.
How to Plant Savoy Cabbage
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Savoy Cabbage
Sow every 8 weeks. Last sowing by Jun 06 to harvest before frost.
For a dedicated fall crop, sow by Jul 02.
Plant Water Budget
Water stress score is 6/10 — 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 | — | 1.1" | 0" | ❄️ Dormant |
| Feb | — | 0.7" | 0" | ❄️ Dormant |
| Mar | — | 1.2" | 0" | ❄️ Dormant |
| Apr | — | 1.3" | 0" | ❄️ Dormant |
| May | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Jun | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Jul | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Aug | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Sep | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Oct | — | 1.2" | 0" | ❄️ Dormant |
| Nov | — | 1" | 0" | ❄️ Dormant |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Petroleum 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 Planting Timeline — Petroleum County, MT
Savoy Cabbage Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 6 | Apr 6 – Apr 20 |
| Transplant Outdoors | May 18 | May 18 – Jun 1 |
| Direct Sow | May 11 | May 11 – Jun 1 |
| Harvest | July 27 | Jul 27 – Sep 21 |
| Fall Sowing | July 2 | Jul 2 – Jul 16 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
70–110 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 4b
📆 Growing Season
129 days in Petroleum County
Growing Tips for Savoy Cabbage in Petroleum County
Direct sow Savoy Cabbage outdoors after May 18 in Petroleum County when soil has warmed and frost danger has passed.
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.
Petroleum County receives only 14" 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
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Check more plant combinations with our Companion Planting Checker →
Savoy Cabbage in Other Locations
Frequently Asked Questions
When should I plant Savoy Cabbage in Petroleum County, MT?
Petroleum County is in Zone 4b with an average last frost of May 18. Plan your Savoy Cabbage planting based on this frost date — see the calendar above for exact timing.
What planting zone is Petroleum County, MT?
Petroleum County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 18 and first fall frost is September 24.
Your Petroleum County Garden Planner — Free
A 24-page printable planner built for Petroleum 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.