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When to plant Lemon Thyme in Washington County, IL

In Washington County, Lemon Thyme is a single-season spring crop — there's no second fall window. Plant April 16–April 30 for an 70–90-day harvest, finishing well before the October 20 first frost.

When to Plant Lemon Thyme in Washington County, IL

Lemon thyme is a low-growing perennial herb with tiny, citrus-scented leaves. It combines the savory quality of thyme with a bright lemon flavor, excellent with fish and poultry.

Washington County, Illinois is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 20, giving you a growing season of approximately 194 days.

At an elevation of 1,126 feet, Washington County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Lemon Thyme during the growing season.

Washington County, IL (Zone 6b) Moderate season
194 days
Last Spring Frost April 9
194 growing days
First Fall Frost October 20

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Lemon Thyme Planting Timeline — Washington County, IL

Lemon Thyme Planting Calendar

Activity When Date Range
Transplant Outdoors April 16 Apr 16 – Apr 30
Harvest June 25 Jun 25 – Aug 27

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
May
June Harvest
July Harvest
August Harvest
September
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 6b

📆 Growing Season

194 days in Washington County

Growing Tips for Washington County

Start from cuttings or divisions. Plant in well-drained soil. Trim back after flowering. Use as a fragrant ground cover or edging plant along garden paths.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lemon Thyme in Washington County, IL?

Washington County is in Zone 6b with an average last frost of April 9. Plan your Lemon Thyme planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, IL?

Washington County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 9 and first fall frost is October 20.

When should I plant Lemon Thyme in Washington County, IL?

In Washington County, IL, plant Lemon Thyme after the last frost (around April 9) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Washington County, IL for Lemon Thyme?

Washington County sits in USDA Zone 6b. Lemon Thyme grows reliably in zones 5a through 9b, so it's a good fit here.

Can Lemon Thyme grow in Washington County's climate?

Yes — Lemon Thyme grows well in Washington County's temperate climate. Washington County averages a 194-day frost-free season, with last frost around April 9 and first frost around October 20.

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Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington County (Zone 6b). 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, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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