When to Plant Tarragon in Harmon County, OK
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.
Harmon County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is November 5, giving you a growing season of approximately 219 days.
At an elevation of 993 feet, Harmon County receives approximately 34.4 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Tarragon during the growing season.
Harmon County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.5
Drainage
Well Drained
Plant Planting Risk Windows
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 Harmon County
How your county's soil matches Tarragon's growing requirements.
Soil pH
Your soil pH (6.5–7.5) is within Tarragon's preferred range (6.0–7.5).
Soil Texture
The loam soil in Harmon County is excellent for Tarragon — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.0%) — Tarragon will thrive.
How to Plant Tarragon
Succession Planting Tarragon
Sow every 6.9 weeks. Last sowing by Aug 07 to harvest before frost.
Plant Water Budget
Water stress score is 8/10 — 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 | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | 1.7" | 2.3" | 0" | ✅ Rainfall sufficient |
| Apr | 1.7" | 3.7" | 0" | ✅ Rainfall sufficient |
| May | 1.7" | 5.1" | 0" | ✅ Rainfall sufficient |
| Jun | 1.7" | 5" | 0" | ✅ Rainfall sufficient |
| Jul | 1.7" | 4.1" | 0" | ✅ Rainfall sufficient |
| Aug | 1.7" | 4.8" | 0" | ✅ Rainfall sufficient |
| Sep | 1.7" | 3" | 0" | ✅ Rainfall sufficient |
| Oct | 1.7" | 2" | 0" | ✅ Rainfall sufficient |
| Nov | 1.7" | 1.3" | 0.4" | 💧 Light watering |
| Dec | — | 1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Harmon County). 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 Planting Timeline — Harmon County, OK
Tarragon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 7 | Apr 7 – Apr 21 |
| Harvest | June 9 | Jun 9 – Aug 18 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| 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: ideal
🗺️ USDA Zone
Zone 7b
📆 Growing Season
219 days in Harmon County
Growing Tips for Tarragon in Harmon County
Direct sow Tarragon outdoors after March 31 in Harmon 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 →
Tarragon in Other Locations
Frequently Asked Questions
When should I plant Tarragon in Harmon County, OK?
Harmon County is in Zone 7b with an average last frost of March 31. Plan your Tarragon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Harmon County, OK?
Harmon County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is November 5.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Harmon County gardeners in Zone 7b 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.