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When to Plant Oregano in Campbell County, WY

Oregano is a robust perennial herb essential to Italian and Greek cuisine. Its pungent, savory leaves intensify in flavor when dried.

Campbell County, Wyoming is in USDA Zone 4a. 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 8,132 feet, Campbell County receives approximately 22.3 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Oregano to ensure they mature before fall.

Campbell County, WY (Zone 4a) Short season
123 days
Last Spring Frost May 20
123 growing days
First Fall Frost September 20

Campbell County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 21 🍅 Harvest: Jul 23 – Oct 1
Recommended (50%) ✗ May not fit
Transplant: May 27 🍅 Harvest: Jul 29 – Oct 7
Safe Start (90%) ✗ May not fit
Transplant: Jun 14 🍅 Harvest: Aug 16 – Oct 25

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 Campbell County

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

Soil pH

Your soil pH (6.7โ€“7.6) is within Oregano's preferred range (6.0โ€“8.0).

Soil Texture

The loam soil in Campbell County is excellent for Oregano โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Oregano.

How to Plant Oregano

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

Succession Planting Oregano

2
successive plantings in your 123-day season

Sow every 6.9 weeks. Last sowing by Jun 22 to harvest before frost.

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Oregano

Oregano needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.

Month Oregano Needs Rainfall You Supplement Action
Jan โ€” 1.7" 0" โ„๏ธ Dormant
Feb โ€” 1.2" 0" โ„๏ธ Dormant
Mar โ€” 1.9" 0" โ„๏ธ Dormant
Apr โ€” 2.4" 0" โ„๏ธ Dormant
May 1.3" 2.7" 0" โœ… Rainfall sufficient
Jun 1.3" 1.4" 0" โœ… Rainfall sufficient
Jul 1.3" 2" 0" โœ… Rainfall sufficient
Aug 1.3" 2.4" 0" โœ… Rainfall sufficient
Sep 1.3" 1.6" 0" โœ… Rainfall sufficient
Oct โ€” 2.2" 0" โ„๏ธ Dormant
Nov โ€” 1.5" 0" โ„๏ธ Dormant
Dec โ€” 1.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Campbell County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Oregano 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" โ€” every day above 50ยฐF 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.

Oregano needs ~919 GDD — county provides 1,506 GDD Excellent fit

Oregano Planting Timeline โ€” Campbell County, WY

Oregano Planting Calendar

Activity When Date Range
Transplant Outdoors May 27 May 27 โ€“ Jun 10
Harvest July 29 Jul 29 โ€“ Oct 7

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Transplant Outdoors
June Transplant Outdoors
July Harvest
August Harvest
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.3"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“8 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

123 days in Campbell County

Growing Tips for Oregano in Campbell County

Direct sow Oregano outdoors after May 20 in Campbell County when soil has warmed and frost danger has passed.

General growing tips

Start from seed, cuttings, or divisions. Harvest just before flowering for strongest flavor. Cut plants back to a few inches in spring to encourage vigorous new growth.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Oregano in Campbell County, WY?

Campbell County is in Zone 4a with an average last frost of May 20. Plan your Oregano planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Campbell County, WY?

Campbell County, Wyoming is in USDA Hardiness Zone 4a. The average last spring frost is May 20 and first fall frost is September 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Campbell County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Campbell County, WY. Local conditions may vary. Last updated: April 2026.