When to Plant Tarragon in Castro 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.
Castro County, Texas is in USDA Zone 7a. The average last spring frost is April 14 and the first fall frost is October 24, giving you a growing season of approximately 193 days.
At an elevation of 3,838 feet, Castro County receives approximately 47.6 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°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.
Castro County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.5-8.1
Drainage
Well Drained
Monthly Watering Guide for Tarragon
Tarragon needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Tarragon Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.3" | 0" | ❄️ Dormant |
| Feb | — | 2.7" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| May | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Jun | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Jul | 4.3" | 8" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 8.9" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 6.8" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 3.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Castro County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Tarragon Planting Timeline — Castro County, TX
Tarragon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 21 | Apr 21 – May 5 |
| Harvest | June 23 | Jun 23 – Sep 1 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | Transplant Outdoors |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 7a
📆 Growing Season
193 days in Castro County
Growing Tips for Castro County
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 →
Tarragon in Other Locations
Frequently Asked Questions
When should I plant Tarragon in Castro County, TX?
Castro County is in Zone 7a with an average last frost of April 14. Plan your Tarragon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Castro County, TX?
Castro County, Texas is in USDA Hardiness Zone 7a. The average last spring frost is April 14 and first fall frost is October 24.
Your Castro County Garden Planner — Free
A 22-page printable planner built for Castro County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.