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When to plant Thyme in Guthrie County, IA

Plant Thyme in Guthrie County, between May 3 and May 17 — the only viable window. Zone 5a's short season (163 frost-free days) rules out a fall crop.

When to Plant Thyme in Guthrie County, IA

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.

Guthrie County, Iowa is in USDA Zone 5a. The average last spring frost is April 26 and the first fall frost is October 6, giving you a growing season of approximately 163 days.

At an elevation of 1,378 feet, Guthrie County receives approximately 31.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Thyme to ensure they mature before fall.

Guthrie County, IA (Zone 5a) Moderate season
163 days
Last Spring Frost April 26
163 growing days
First Fall Frost October 6

Guthrie County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Thyme Planting Timeline — Guthrie County, IA

Thyme Planting Calendar

Activity When Date Range
Transplant Outdoors May 3 May 3 – May 17
Harvest July 12 Jul 12 – Sep 13

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
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

163 days in Guthrie County

Growing Tips for Guthrie 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 Guthrie County, IA?

Guthrie County is in Zone 5a with an average last frost of April 26. Plan your Thyme planting based on this frost date — see the calendar above for exact timing.

What planting zone is Guthrie County, IA?

Guthrie County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 26 and first fall frost is October 6.

When should I plant Thyme in Guthrie County, IA?

In Guthrie County, IA, plant Thyme after the last frost (around April 26) and before the first frost (around October 6). Best results when soil holds above 50°F.

What growing zone is Guthrie County, IA for Thyme?

Guthrie 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 Guthrie County's climate?

Yes — Thyme grows well in Guthrie County's temperate climate. Guthrie County averages a 163-day frost-free season, with last frost around April 26 and first frost around October 6.

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Your Guthrie County Garden Planner — Free

A 22-page printable planner built for Guthrie 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 Guthrie County, IA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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