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When to Plant Savory in Petroleum County, MT

Petroleum County, Montana Zone 4b May

Your May gardening checklist

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Petroleum County, Montana.

Avg. last frost May 18
Avg. first frost September 24
Soil temp (4") 30°F
Watering High
Pest pressure Low
Daylight 14.9 hrs
  1. Move savory into the garden

    Frost risk is low now in Petroleum County, Montana. If you've been covering beds overnight, you can stop.

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Summer savory is an annual herb with a peppery, thyme-like flavor that pairs especially well with beans. Winter savory is a perennial with a stronger flavor.

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 Savory to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Savory successfully. Mulch heavily to conserve soil moisture.

Petroleum County, MT (Zone 4b) Short season
129 days
Last Spring Frost May 18
129 growing days
First Fall Frost September 24
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Petroleum County Soil Profile

Soil Type

Loam

Soil pH

6.8-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Transplant: May 18 🍅 Harvest: Jul 13 – Sep 7
Recommended (50%) ✓ Fits season (10 days to spare)
Transplant: May 25 🍅 Harvest: Jul 20 – Sep 14
Safe Start (90%) ✓ Fits season (13 days to spare)
Transplant: Jun 6 🍅 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 Petroleum County

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

Soil pH

Your soil pH (6.8–8.2) overlaps with Savory's range (6.5–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Savory.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Savory.

How to Plant Savory

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Savory

2
successive plantings in your 129-day season

Sow every 5.7 weeks. Last sowing by Jul 16 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 281 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Savory

Savory needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Savory 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 2.2" 1.8" 0.4" 💧 Light watering
Jun 2.2" 0.9" 1.3" 🚿 Regular watering
Jul 2.2" 1.2" 1" 💧 Light watering
Aug 2.2" 1.5" 0.7" 💧 Light watering
Sep 2.2" 1.2" 1" 💧 Light 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.

Savory 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.

Savory needs ~645 GDD — county provides 1,386 GDD Excellent fit

Savory Planting Timeline — Petroleum County, MT

Savory Planting Calendar

Activity When Date Range
Transplant Outdoors May 25 May 25 – Jun 8
Harvest July 20 Jul 20 – Sep 14

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
July Harvest
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

129 days in Petroleum County

Growing Tips for Savory in Petroleum County

Direct sow Savory outdoors after May 18 in Petroleum County when soil has warmed and frost danger has passed.

Petroleum County receives only 14" of rain annually. Savory needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow summer savory after last frost. Plant winter savory from divisions or cuttings. Harvest stems before flowering for best flavor. Use fresh or dried.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Savory in Petroleum County, MT?

Petroleum County is in Zone 4b with an average last frost of May 18. Plan your Savory 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.

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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.

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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 Petroleum County, MT. Local conditions may vary. Last updated: May 2026.

Sources & credits

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