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When to plant Tarragon in Bureau County, IL

Bureau County sits in cold Zone 5b. Plant Tarragon April 29–May 13 for the single annual harvest; the October 14 first frost closes the window.

When to Plant Tarragon in Bureau 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.

Bureau County, Illinois is in USDA Zone 5b. The average last spring frost is April 22 and the first fall frost is October 14, giving you a growing season of approximately 175 days.

At an elevation of 613 feet, Bureau County receives approximately 34.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Tarragon to ensure they mature before fall.

Bureau County, IL (Zone 5b) Moderate season
175 days
Last Spring Frost April 22
175 growing days
First Fall Frost October 14

Bureau County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.7

Drainage

Well Drained

Monthly Watering Guide for Tarragon

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

Month Tarragon Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 4.7" 0" ✅ Rainfall sufficient
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

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

Tarragon Planting Timeline — Bureau County, IL

Tarragon Planting Calendar

Activity When Date Range
Transplant Outdoors April 29 Apr 29 – May 13
Harvest July 1 Jul 1 – Sep 9

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

Month-by-Month Timeline

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

175 days in Bureau County

Growing Tips for Bureau 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 Bureau County, IL?

Bureau County is in Zone 5b with an average last frost of April 22. Plan your Tarragon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bureau County, IL?

Bureau County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 22 and first fall frost is October 14.

When should I plant Tarragon in Bureau County, IL?

In Bureau County, IL, plant Tarragon after the last frost (around April 22) and before the first frost (around October 14). Best results when soil holds above 50°F.

What growing zone is Bureau County, IL for Tarragon?

Bureau 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 Bureau County's climate?

Yes — Tarragon grows well in Bureau County's temperate climate. Bureau County averages a 175-day frost-free season, with last frost around April 22 and first frost around October 14.

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Your Bureau County Garden Planner — Free

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

Sources & credits

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