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When to Plant Tarragon in Marquette County, MI

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.

Marquette County, Michigan is in USDA Zone 4a. The average last spring frost is May 10 and the first fall frost is October 20, giving you a growing season of approximately 163 days.

At an elevation of 564 feet, Marquette County receives approximately 36.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Tarragon to ensure they mature before fall.

Marquette County, MI (Zone 4a) Moderate season
163 days
Last Spring Frost May 10
163 growing days
First Fall Frost October 20

Marquette County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (22 days to spare)
Transplant: May 9 🍅 Harvest: Jul 11 – Sep 19
Recommended (50%) ✓ Fits season (23 days to spare)
Transplant: May 17 🍅 Harvest: Jul 19 – Sep 27
Safe Start (90%) ✓ Fits season (23 days to spare)
Transplant: Jun 3 🍅 Harvest: Aug 5 – Oct 14

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 Marquette County

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

Soil pH

Your soil pH (6.0โ€“6.8) is within Tarragon's preferred range (6.0โ€“7.5).

Soil Texture

The silt loam soil in Marquette County is excellent for Tarragon โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.1%) โ€” 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 163-day season

Sow every 6.9 weeks. Last sowing by Jul 22 to harvest before frost.

Plant Water Budget

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

Water stress score is 6/10 โ€” 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 โ€” 1.5" 0" โ„๏ธ Dormant
Feb โ€” 1.8" 0" โ„๏ธ Dormant
Mar โ€” 2.6" 0" โ„๏ธ Dormant
Apr โ€” 4" 0" โ„๏ธ Dormant
May 1.7" 4.5" 0" โœ… Rainfall sufficient
Jun 1.7" 4.3" 0" โœ… Rainfall sufficient
Jul 1.7" 3.6" 0" โœ… Rainfall sufficient
Aug 1.7" 3.4" 0" โœ… Rainfall sufficient
Sep 1.7" 2.9" 0" โœ… Rainfall sufficient
Oct 1.7" 3.2" 0" โœ… Rainfall sufficient
Nov โ€” 2.4" 0" โ„๏ธ Dormant
Dec โ€” 2.3" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Marquette County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~806 GDD — county provides 1,752 GDD Excellent fit

Tarragon Planting Timeline โ€” Marquette County, MI

Tarragon Planting Calendar

Activity When Date Range
Transplant Outdoors May 17 May 17 โ€“ May 31
Harvest July 19 Jul 19 โ€“ Sep 27

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.4"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

163 days in Marquette County

Growing Tips for Tarragon in Marquette County

Direct sow Tarragon outdoors after May 10 in Marquette 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 Marquette County, MI?

Marquette County is in Zone 4a with an average last frost of May 10. Plan your Tarragon planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Marquette County, MI?

Marquette County, Michigan is in USDA Hardiness Zone 4a. The average last spring frost is May 10 and first fall frost is October 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Marquette County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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