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When to Plant Tarragon in Gratiot County, MI

Gratiot County, Michigan Zone 6a April

April in the garden — Gratiot County, Michigan

Welcome to April in Zone 6a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 30
Avg. first frost October 16
Soil temp (4") 46°F
Watering Low
Pest pressure Low
Daylight 13.2 hrs
Coming up in May — start thinking about
  • Transplants going out: tarragon

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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.

Gratiot County, Michigan is in USDA Zone 6a. The average last spring frost is April 30 and the first fall frost is October 16, giving you a growing season of approximately 169 days.

At an elevation of 1,055 feet, Gratiot County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Tarragon to ensure they mature before fall.

Gratiot County, MI (Zone 6a) Moderate season
169 days
Last Spring Frost April 30
169 growing days
First Fall Frost October 16

Gratiot County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (22 days to spare)
Transplant: May 4 🍅 Harvest: Jul 6 – Sep 14
Recommended (50%) ✓ Fits season (29 days to spare)
Transplant: May 7 🍅 Harvest: Jul 9 – Sep 17
Safe Start (90%) ✓ Fits season (27 days to spare)
Transplant: May 23 🍅 Harvest: Jul 25 – Oct 3

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Gratiot County

How your county's soil matches Tarragon's growing requirements.

Soil pH

Your soil pH (6.2–6.8) is within Tarragon's preferred range (6.0–7.5).

Soil Texture

The silt loam soil in Gratiot County is excellent for Tarragon — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.7%) — Tarragon will thrive.

How to Plant Tarragon

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Tarragon

3
successive plantings in your 169-day season

Sow every 6.9 weeks. Last sowing by Jul 18 to harvest before frost.

Plant Water Budget

Plant needs
0.4″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Tarragon

Tarragon needs approximately 0.4 inches of water per week (1.7" per month). Here's how your county's rainfall compares month by month.

Month Tarragon Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 1.7" 3.9" 0" ✅ Rainfall sufficient
May 1.7" 3.9" 0" ✅ Rainfall sufficient
Jun 1.7" 5.3" 0" ✅ Rainfall sufficient
Jul 1.7" 3.7" 0" ✅ Rainfall sufficient
Aug 1.7" 4.4" 0" ✅ Rainfall sufficient
Sep 1.7" 3.7" 0" ✅ Rainfall sufficient
Oct 1.7" 2.8" 0" ✅ Rainfall sufficient
Nov 3" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

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

Tarragon Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Tarragon needs ~919 GDD — county provides 2,070 GDD Excellent fit

Tarragon Planting Timeline — Gratiot County, MI

Tarragon Planting Calendar

Activity When Date Range
Transplant Outdoors May 7 May 7 – May 21
Harvest July 9 Jul 9 – Sep 17

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

0.4"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

169 days in Gratiot County

Growing Tips for Tarragon in Gratiot County

Direct sow Tarragon outdoors after April 30 in Gratiot County when soil has warmed and frost danger has passed.

Common pests for Tarragon in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

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 Gratiot County, MI?

Gratiot County is in Zone 6a with an average last frost of April 30. Plan your Tarragon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Gratiot County, MI?

Gratiot County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is April 30 and first fall frost is October 16.

🌱

Your Gratiot County Garden Planner — Free

A 24-page printable planner built for Gratiot County (Zone 6a). 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 Gratiot County, MI. Local conditions may vary. Last updated: April 2026.

Sources & credits

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