Blog

When to Plant Tarragon in Hillsdale County, MI

Hillsdale County, Michigan Zone 6a May

Your May game plan for Hillsdale County, Michigan

We've pulled the most time-sensitive tasks for Hillsdale County, Michigan this May and put them front and centre. Tackle them in order.

Avg. last frost April 29
Avg. first frost October 14
Soil temp (4") 59°F
Watering Low
Pest pressure Low
Daylight 14.4 hrs
  1. Get tarragon in the ground

    Your last frost (April 29) has passed. These warm-season crops can handle outdoor soil now.

Instant PDF download. No spam, unsubscribe any time.

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.

Hillsdale County, Michigan is in USDA Zone 6a. The average last spring frost is April 29 and the first fall frost is October 14, giving you a growing season of approximately 168 days.

At an elevation of 1,173 feet, Hillsdale County receives approximately 41.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Tarragon during the growing season.

Hillsdale County, MI (Zone 6a) Moderate season
168 days
Last Spring Frost April 29
168 growing days
First Fall Frost October 14
Share this guide:

Hillsdale County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (25 days to spare)
Transplant: May 3 🍅 Harvest: Jul 5 – Sep 13
Recommended (50%) ✓ Fits season (28 days to spare)
Transplant: May 6 🍅 Harvest: Jul 8 – Sep 16
Safe Start (90%) ✓ Fits season (22 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 Hillsdale County

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

Soil pH

Your soil pH (5.9–6.8) overlaps with Tarragon's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Tarragon.

How to Plant Tarragon

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

Succession Planting Tarragon

3
successive plantings in your 168-day season

Sow every 6.9 weeks. Last sowing by Jul 16 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
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.6" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 1.7" 3.7" 0" ✅ Rainfall sufficient
May 1.7" 5" 0" ✅ Rainfall sufficient
Jun 1.7" 5.7" 0" ✅ Rainfall sufficient
Jul 1.7" 4" 0" ✅ Rainfall sufficient
Aug 1.7" 3.8" 0" ✅ Rainfall sufficient
Sep 1.7" 3.8" 0" ✅ Rainfall sufficient
Oct 1.7" 3.1" 0" ✅ Rainfall sufficient
Nov 3.2" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Hillsdale 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 ~1,031 GDD — county provides 2,310 GDD Excellent fit

Tarragon Planting Timeline — Hillsdale County, MI

Tarragon Planting Calendar

Activity When Date Range
Transplant Outdoors May 6 May 6 – May 20
Harvest July 8 Jul 8 – Sep 16

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
Share this guide:

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: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

168 days in Hillsdale County

Growing Tips for Tarragon in Hillsdale County

Direct sow Tarragon outdoors after April 29 in Hillsdale 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 Hillsdale County, MI?

Hillsdale County is in Zone 6a with an average last frost of April 29. Plan your Tarragon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hillsdale County, MI?

Hillsdale County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is April 29 and first fall frost is October 14.

🌱

Your Hillsdale County Garden Planner — Free

A 24-page printable planner built for Hillsdale 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Hillsdale County, MI. Local conditions may vary. Last updated: May 2026.

Sources & credits

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