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When to plant Thyme in Washington County, MN

Plant Thyme in Washington County, between April 30 and May 14 — the only viable window. Zone 5a's short season (169 frost-free days) rules out a fall crop.

When to Plant Thyme in Washington County, MN

Thyme

Thyme is a low-growing perennial herb with tiny, aromatic leaves and a warm, earthy flavor. It is one of the most versatile culinary and medicinal herbs.

Washington County, Minnesota is in USDA Zone 5a. The average last spring frost is April 23 and the first fall frost is October 9, giving you a growing season of approximately 169 days.

At an elevation of 832 feet, Washington County receives approximately 30.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Thyme during the growing season.

Washington County, MN (Zone 5a) Moderate season
169 days
Last Spring Frost April 23
169 growing days
First Fall Frost October 9

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Thyme Planting Timeline — Washington County, MN

Thyme Planting Calendar

Activity When Date Range
Transplant Outdoors April 30 Apr 30 – May 14
Harvest July 9 Jul 9 – Sep 10

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–8 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

169 days in Washington County

Growing Tips for Washington County

Start from seed, cuttings, or divisions. Plant in well-drained, lean soil. Prune lightly after flowering. Replace plants every 3-4 years when they become woody.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Thyme in Washington County, MN?

Washington County is in Zone 5a with an average last frost of April 23. Plan your Thyme planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, MN?

Washington County, Minnesota is in USDA Hardiness Zone 5a. The average last spring frost is April 23 and first fall frost is October 9.

When should I plant Thyme in Washington County, MN?

In Washington County, MN, plant Thyme after the last frost (around April 23) and before the first frost (around October 9). Best results when soil holds above 50°F.

What growing zone is Washington County, MN for Thyme?

Washington County sits in USDA Zone 5a. Thyme grows reliably in zones 4a through 9b, so it's a good fit here.

Can Thyme grow in Washington County's climate?

Yes — Thyme grows well in Washington County's temperate climate. Washington County averages a 169-day frost-free season, with last frost around April 23 and first frost around October 9.

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Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington County (Zone 5a). 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 Washington County, MN. Local conditions may vary. Last updated: June 2026.

Sources & credits

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