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When to Plant Tarragon in DeKalb County, AL

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.

DeKalb County, Alabama is in USDA Zone 7a. The average last spring frost is April 1 and the first fall frost is October 31, giving you a growing season of approximately 213 days.

At an elevation of 393 feet, DeKalb County receives approximately 56.2 inches of rainfall annually with predominantly clay loam soil. Summer highs average 91ยฐF, providing good warmth for Tarragon during the growing season. Clay soil retains moisture well for Tarragon, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Tarragon root diseases.

DeKalb County, AL (Zone 7a) Long season
213 days
Last Spring Frost April 1
213 growing days
First Fall Frost October 31

DeKalb County Soil Profile

Soil Type

Clay Loam

Soil pH

5.5-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (72 days to spare)
Transplant: Apr 2 🍅 Harvest: Jun 4 – Aug 13
Recommended (50%) ✓ Fits season (73 days to spare)
Transplant: Apr 8 🍅 Harvest: Jun 10 – Aug 19
Safe Start (90%) ✓ Fits season (70 days to spare)
Transplant: Apr 25 🍅 Harvest: Jun 27 – Sep 5

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 DeKalb County

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

Soil pH

Your soil pH (5.5โ€“6.8) overlaps with Tarragon's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Tarragon.

How to Plant Tarragon

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

Succession Planting Tarragon

4
successive plantings in your 213-day season

Sow every 6.9 weeks. Last sowing by Aug 02 to harvest before frost.

Plant Water Budget

Plant needs
0.4″/week
Rainfall provides
1.1″/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€” 4.7" 0" โ„๏ธ Dormant
Feb โ€” 4.1" 0" โ„๏ธ Dormant
Mar โ€” 5.9" 0" โ„๏ธ Dormant
Apr 1.7" 4" 0" โœ… Rainfall sufficient
May 1.7" 4.3" 0" โœ… Rainfall sufficient
Jun 1.7" 5.8" 0" โœ… Rainfall sufficient
Jul 1.7" 5.8" 0" โœ… Rainfall sufficient
Aug 1.7" 5" 0" โœ… Rainfall sufficient
Sep 1.7" 3.7" 0" โœ… Rainfall sufficient
Oct 1.7" 3.2" 0" โœ… Rainfall sufficient
Nov โ€” 4.6" 0" โ„๏ธ Dormant
Dec โ€” 5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in DeKalb 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 ~1,369 GDD — county provides 3,887 GDD Excellent fit

Tarragon Planting Timeline โ€” DeKalb County, AL

Tarragon Planting Calendar

Activity When Date Range
Transplant Outdoors April 8 Apr 8 โ€“ Apr 22
Harvest June 10 Jun 10 โ€“ Aug 19

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Transplant Outdoors
May โ€”
June Harvest
July Harvest
August Harvest
September โ€”
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: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

213 days in DeKalb County

Growing Tips for Tarragon in DeKalb County

Direct sow Tarragon outdoors after April 01 in DeKalb County when soil has warmed and frost danger has passed.

With DeKalb County's clay soil (28% clay), work in 3-4 inches of compost before planting Tarragon. Avoid tilling when soil is wet to prevent compaction.

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

With 56" of annual rainfall in DeKalb County, ensure good drainage for Tarragon โ€” excess moisture can promote root rot and fungal diseases.

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 DeKalb County, AL?

DeKalb County is in Zone 7a with an average last frost of April 1. Plan your Tarragon planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is DeKalb County, AL?

DeKalb County, Alabama is in USDA Hardiness Zone 7a. The average last spring frost is April 1 and first fall frost is October 31.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help DeKalb County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

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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 DeKalb County, AL. Local conditions may vary. Last updated: April 2026.