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When to Plant Tarragon in Armstrong County, TX

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.

Armstrong County, Texas is in USDA Zone 7a. The average last spring frost is April 15 and the first fall frost is October 24, giving you a growing season of approximately 192 days.

At an elevation of 2,506 feet, Armstrong County receives approximately 57.6 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 102ยฐF, so Tarragon may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” 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.

Armstrong County, TX (Zone 7a) Moderate season
192 days
Last Spring Frost April 15
192 growing days
First Fall Frost October 24

Armstrong County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (50 days to spare)
Transplant: Apr 18 🍅 Harvest: Jun 20 – Aug 29
Recommended (50%) ✓ Fits season (52 days to spare)
Transplant: Apr 22 🍅 Harvest: Jun 24 – Sep 2
Safe Start (90%) ✓ Fits season (48 days to spare)
Transplant: May 8 🍅 Harvest: Jul 10 – Sep 18

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 Armstrong County

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

Soil pH

Your soil pH (7.2โ€“8.3) is more alkaline than Tarragon prefers (6.0โ€“7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Armstrong County 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 (0.9%). 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

3
successive plantings in your 192-day season

Sow every 6.9 weeks. Last sowing by Jul 26 to harvest before frost.

Plant Water Budget

Plant needs
0.4″/week
Rainfall provides
1.3″/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€” 3.6" 0" โ„๏ธ Dormant
Feb โ€” 3.6" 0" โ„๏ธ Dormant
Mar โ€” 3" 0" โ„๏ธ Dormant
Apr 1.7" 2.2" 0" โœ… Rainfall sufficient
May 1.7" 1.4" 0.3" ๐Ÿ’ง Light watering
Jun 1.7" 1.9" 0" โœ… Rainfall sufficient
Jul 1.7" 8.8" 0" โœ… Rainfall sufficient
Aug 1.7" 13.9" 0" โœ… Rainfall sufficient
Sep 1.7" 6.9" 0" โœ… Rainfall sufficient
Oct 1.7" 5" 0" โœ… Rainfall sufficient
Nov โ€” 3.2" 0" โ„๏ธ Dormant
Dec โ€” 4.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Armstrong 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 ~1,988 GDD — county provides 5,088 GDD Excellent fit

Tarragon Planting Timeline โ€” Armstrong County, TX

Tarragon Planting Calendar

Activity When Date Range
Transplant Outdoors April 22 Apr 22 โ€“ May 6
Harvest June 24 Jun 24 โ€“ Sep 2

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 Transplant Outdoors
June Harvest
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: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

192 days in Armstrong County

Growing Tips for Tarragon in Armstrong County

Direct sow Tarragon outdoors after April 15 in Armstrong County when soil has warmed and frost danger has passed.

Sandy soil in Armstrong County dries quickly โ€” 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 102ยฐF in Armstrong County, 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.

With 58" of annual rainfall in Armstrong 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 Armstrong County, TX?

Armstrong County is in Zone 7a with an average last frost of April 15. Plan your Tarragon planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Armstrong County, TX?

Armstrong County, Texas is in USDA Hardiness Zone 7a. The average last spring frost is April 15 and first fall frost is October 24.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Armstrong 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 Armstrong County, TX. Local conditions may vary. Last updated: April 2026.