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When to plant Tarragon in Warren County, IL

Warren County's 191-day season only supports one Tarragon planting per year. Sow between April 20 and May 4 for the best chance at full maturity before October 21.

When to Plant Tarragon in Warren County, IL

French tarragon is a perennial herb with slender leaves and a distinctive anise-like flavor essential in French cooking. It does not produce viable seed and must be propagated vegetatively.

Warren County, Illinois is in USDA Zone 5b. The average last spring frost is April 13 and the first fall frost is October 21, giving you a growing season of approximately 191 days.

At an elevation of 801 feet, Warren County receives approximately 36.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Tarragon during the growing season.

Warren County, IL (Zone 5b) Moderate season
191 days
Last Spring Frost April 13
191 growing days
First Fall Frost October 21

Warren County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Tarragon Planting Timeline — Warren County, IL

Tarragon Planting Calendar

Activity When Date Range
Transplant Outdoors April 20 Apr 20 – May 4
Harvest June 22 Jun 22 – Aug 31

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

191 days in Warren County

Growing Tips for Warren County

Purchase plants or divisions as French tarragon does not grow true from seed. Plant in well-drained soil. Divide every 3-4 years to maintain vigor. Harvest tips regularly for best flavor.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Tarragon in Warren County, IL?

Warren County is in Zone 5b with an average last frost of April 13. Plan your Tarragon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Warren County, IL?

Warren County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 13 and first fall frost is October 21.

When should I plant Tarragon in Warren County, IL?

In Warren County, IL, plant Tarragon after the last frost (around April 13) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Warren County, IL for Tarragon?

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

Can Tarragon grow in Warren County's climate?

Yes — Tarragon grows well in Warren County's temperate climate. Warren County averages a 191-day frost-free season, with last frost around April 13 and first frost around October 21.

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Your Warren County Garden Planner — Free

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

Sources & credits

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