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When to plant Tarragon in Mitchell County, IA

Mitchell County's 157-day season only supports one Tarragon planting per year. Sow between May 10 and May 24 for the best chance at full maturity before October 7.

When to Plant Tarragon in Mitchell County, IA

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.

Mitchell County, Iowa is in USDA Zone 5a. The average last spring frost is May 3 and the first fall frost is October 7, giving you a growing season of approximately 157 days.

At an elevation of 506 feet, Mitchell County receives approximately 36.1 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.

Mitchell County, IA (Zone 5a) Moderate season
157 days
Last Spring Frost May 3
157 growing days
First Fall Frost October 7

Mitchell County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.3

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 1.4" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 3.3" 0" ❄️ Dormant
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 5.1" 0" ✅ Rainfall sufficient
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 2.4" 1.9" 💧 Light watering
Nov 2.8" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

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

Tarragon Planting Timeline — Mitchell County, IA

Tarragon Planting Calendar

Activity When Date Range
Transplant Outdoors May 10 May 10 – May 24
Harvest July 12 Jul 12 – 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

Moderate — regular watering

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

157 days in Mitchell County

Growing Tips for Mitchell 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 Mitchell County, IA?

Mitchell County is in Zone 5a with an average last frost of May 3. Plan your Tarragon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mitchell County, IA?

Mitchell County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 3 and first fall frost is October 7.

When should I plant Tarragon in Mitchell County, IA?

In Mitchell County, IA, plant Tarragon after the last frost (around May 3) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Mitchell County, IA for Tarragon?

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

Can Tarragon grow in Mitchell County's climate?

Yes — Tarragon grows well in Mitchell County's temperate climate. Mitchell County averages a 157-day frost-free season, with last frost around May 3 and first frost around October 7.

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Your Mitchell County Garden Planner — Free

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

Sources & credits

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