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When to Plant Oregano in Wasco County, OR

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

Wasco County, Oregon is in USDA Zone 6b. The average last spring frost is April 23 and the first fall frost is October 12, giving you a growing season of approximately 172 days.

At an elevation of 432 feet, Wasco County receives approximately 35.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Oregano to ensure they mature before fall.

Wasco County, OR (Zone 6b) Moderate season
172 days
Last Spring Frost April 23
172 growing days
First Fall Frost October 12

Wasco County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (34 days to spare)
Transplant: Apr 21 🍅 Harvest: Jun 23 – Sep 1
Recommended (50%) ✓ Fits season (32 days to spare)
Transplant: Apr 30 🍅 Harvest: Jul 2 – Sep 10
Safe Start (90%) ✓ Fits season (29 days to spare)
Transplant: May 20 🍅 Harvest: Jul 22 – 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.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Oregano needs ~750 GDD — county provides 1,720 GDD Excellent fit

Oregano Planting Timeline โ€” Wasco County, OR

Oregano Planting Calendar

Activity When Date Range
Transplant Outdoors April 30 Apr 30 โ€“ May 14
Harvest July 2 Jul 2 โ€“ Sep 10

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

60โ€“90 days

Soil pH

6 โ€“ 8

USDA Zone

Zone 6b

Growing Season

172 days

Growing Tips for Wasco County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Oregano in Wasco County, OR?

Wasco County is in Zone 6b with an average last frost of April 23. Plan your Oregano planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Wasco County, OR?

Wasco County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is April 23 and first fall frost is October 12.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Wasco County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

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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 Wasco County, OR. Local conditions may vary. Last updated: April 2026.