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When to Plant Thyme in Clark County, SD

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.

Clark County, South Dakota is in USDA Zone 4b. The average last spring frost is May 3 and the first fall frost is October 5, giving you a growing season of approximately 155 days.

At an elevation of 799 feet, Clark County receives approximately 28.2 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Thyme to ensure they mature before fall.

Clark County, SD (Zone 4b) Moderate season
155 days
Last Spring Frost May 3
155 growing days
First Fall Frost October 5

Clark County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Thyme Planting Timeline — Clark County, SD

Thyme Planting Calendar

Activity When Date Range
Transplant Outdoors May 10 May 10 – May 24
Harvest July 19 Jul 19 – Sep 20

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 4b

📆 Growing Season

155 days in Clark County

Growing Tips for Clark 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 Clark County, SD?

Clark County is in Zone 4b with an average last frost of May 3. Plan your Thyme planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clark County, SD?

Clark County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 3 and first fall frost is October 5.

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Your Clark County Garden Planner — Free

A 22-page printable planner built for Clark County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Clark County, SD. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.