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When to plant Thyme in Roscommon County, MI

Plant Thyme in Roscommon County during the brief May 22–June 5 window. With 140 frost-free days, fall plantings can't mature before October 2.

When to Plant Thyme in Roscommon County, MI

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.

Roscommon County, Michigan is in USDA Zone 5a. The average last spring frost is May 15 and the first fall frost is October 2, giving you a growing season of approximately 140 days.

At an elevation of 1,298 feet, Roscommon County receives approximately 36 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.

Roscommon County, MI (Zone 5a) Short season
140 days
Last Spring Frost May 15
140 growing days
First Fall Frost October 2

Roscommon County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Monthly Watering Guide for Thyme

Thyme needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Thyme Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 3.5" 0" ❄️ Dormant
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.4" 0" ✅ Rainfall sufficient
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Roscommon County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Thyme Planting Timeline — Roscommon County, MI

Thyme Planting Calendar

Activity When Date Range
Transplant Outdoors May 22 May 22 – Jun 5
Harvest July 31 Jul 31 – Oct 2

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

Month-by-Month Timeline

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

140 days in Roscommon County

Growing Tips for Roscommon 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 Roscommon County, MI?

Roscommon County is in Zone 5a with an average last frost of May 15. Plan your Thyme planting based on this frost date — see the calendar above for exact timing.

What planting zone is Roscommon County, MI?

Roscommon County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 15 and first fall frost is October 2.

When should I plant Thyme in Roscommon County, MI?

In Roscommon County, MI, plant Thyme after the last frost (around May 15) and before the first frost (around October 2). Best results when soil holds above 50°F.

What growing zone is Roscommon County, MI for Thyme?

Roscommon 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 Roscommon County's climate?

Yes — Thyme grows well in Roscommon County's temperate climate. Roscommon County averages a 140-day frost-free season, with last frost around May 15 and first frost around October 2.

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Your Roscommon County Garden Planner — Free

A 22-page printable planner built for Roscommon 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 Roscommon County, MI. Local conditions may vary. Last updated: July 2026.

Sources & credits

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