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When to Plant Marjoram in Yakima County, WA

Sweet marjoram is a tender perennial herb with a delicate, sweet oregano-like flavor. It is a cornerstone of Mediterranean cooking and pairs well with meats and vegetables.

Yakima County, Washington is in USDA Zone 6b. The average last spring frost is May 6 and the first fall frost is October 3, giving you a growing season of approximately 150 days.

At an elevation of 3,150 feet, Yakima County receives approximately 18 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Marjoram during the growing season. With low rainfall, drip irrigation is essential for growing Marjoram successfully. Mulch heavily to conserve soil moisture.

Yakima County, WA (Zone 6b) Moderate season
150 days
Last Spring Frost May 6
150 growing days
First Fall Frost October 3

Yakima County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (10 days to spare)
Transplant: May 7 🍅 Harvest: Jul 9 – Sep 17
Recommended (50%) ✓ Fits season (10 days to spare)
Transplant: May 13 🍅 Harvest: Jul 15 – Sep 23
Safe Start (90%) ✓ Fits season (7 days to spare)
Transplant: Jun 2 🍅 Harvest: Aug 4 – Oct 13

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
1.0″/week
Rainfall provides
0.5″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 662 gal / 100 sq ft
Marjoram needs ~1,088 GDD — county provides 2,175 GDD Excellent fit

Marjoram Planting Timeline โ€” Yakima County, WA

Marjoram Planting Calendar

Activity When Date Range
Transplant Outdoors May 13 May 13 โ€“ May 27
Harvest July 15 Jul 15 โ€“ Sep 23

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 โ€”
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“90 days

Soil pH

6.5 โ€“ 7.5

USDA Zone

Zone 6b

Growing Season

150 days

Growing Tips for Yakima County

Start seeds indoors 6-8 weeks before last frost. Harvest stems just as flower buds appear for peak flavor. In cold climates, grow as an annual or bring containers indoors.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Marjoram in Yakima County, WA?

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

What planting zone is Yakima County, WA?

Yakima County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is May 6 and first fall frost is October 3.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Yakima 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 Yakima County, WA. Local conditions may vary. Last updated: April 2026.