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When to Plant Tarragon in St. James Parish, LA

St. James Parish, Louisiana Zone 9a May

Your May game plan for St. James Parish, Louisiana

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in St. James Parish, Louisiana.

Avg. last frost February 13
Avg. first frost December 6
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Collect tarragon at their peak

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

To set up a strong June, finish these tasks
  • First harvests: 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.

St. James Parish, Louisiana is in USDA Zone 9a. The average last spring frost is February 13 and the first fall frost is December 6, giving you a growing season of approximately 296 days.

At an elevation of 471 feet, St. James Parish receives approximately 52 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 97°F, so Tarragon may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Tarragon will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Tarragon root diseases.

St. James Parish, LA (Zone 9a) Year-round
296 days
Last Spring Frost February 13
296 growing days
First Fall Frost December 6

St. James Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

5-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (166 days to spare)
Transplant: Feb 1 🍅 Harvest: Apr 5 – Jun 14
Recommended (50%) ✓ Fits season (156 days to spare)
Transplant: Feb 20 🍅 Harvest: Apr 24 – Jul 3
Safe Start (90%) ✓ Fits season (146 days to spare)
Transplant: Mar 16 🍅 Harvest: May 18 – Jul 27

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 St. James Parish

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

Soil pH

Your soil pH (5.0–6.2) is more acidic than Tarragon prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in St. James Parish warms quickly in spring but drains fast. Tarragon will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (2.0%). Add 2-3 inches of compost before planting Tarragon.

How to Plant Tarragon

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

Succession Planting Tarragon

5
successive plantings in your 296-day season

Sow every 6.9 weeks. Last sowing by Sep 07 to harvest before frost.

Plant Water Budget

Plant needs
0.4″/week
Rainfall provides
0.7″/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 4.2" 0" ❄️ Dormant
Feb 1.7" 4.4" 0" ✅ Rainfall sufficient
Mar 1.7" 4.9" 0" ✅ Rainfall sufficient
Apr 1.7" 3.4" 0" ✅ Rainfall sufficient
May 1.7" 4.6" 0" ✅ Rainfall sufficient
Jun 1.7" 4.9" 0" ✅ Rainfall sufficient
Jul 1.7" 5.4" 0" ✅ Rainfall sufficient
Aug 1.7" 5.4" 0" ✅ Rainfall sufficient
Sep 1.7" 3.9" 0" ✅ Rainfall sufficient
Oct 1.7" 2.9" 0" ✅ Rainfall sufficient
Nov 1.7" 4.2" 0" ✅ Rainfall sufficient
Dec 1.7" 3.8" 0" ✅ Rainfall sufficient

Water needs are for active growing months only (Feb–Dec in St. James Parish). 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 ~1,706 GDD — county provides 6,756 GDD Excellent fit

Tarragon Planting Timeline — St. James Parish, LA

Tarragon Planting Calendar

Activity When Date Range
Transplant Outdoors February 20 Feb 20 – Mar 6
Harvest April 24 Apr 24 – Jul 3

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

Month-by-Month Timeline

MonthActivities
January
February Transplant Outdoors
March Transplant Outdoors
April Harvest
May Harvest
June Harvest
July Harvest
August
September
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: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

296 days in St. James Parish

Growing Tips for Tarragon in St. James Parish

Direct sow Tarragon outdoors after February 13 in St. James Parish when soil has warmed and frost danger has passed.

Sandy soil in St. James Parish dries quickly — mulch Tarragon with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 97°F in St. James Parish, provide afternoon shade for Tarragon and water deeply in the morning.

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 St. James Parish, LA?

St. James Parish is in Zone 9a with an average last frost of February 13. Plan your Tarragon planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. James Parish, LA?

St. James Parish, Louisiana is in USDA Hardiness Zone 9a. The average last spring frost is February 13 and first fall frost is December 6.

🌱

Your St. James Parish Garden Planner — Free

A 24-page printable planner built for St. James Parish (Zone 9a). 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 St. James Parish, LA. Local conditions may vary. Last updated: May 2026.

Sources & credits

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