When to Plant Tarragon in Harney County, OR
Your May game plan for Harney County, Oregon
We've pulled the most time-sensitive tasks for Harney County, Oregon this May and put them front and centre. Tackle them in order.
A few tasks this May that'll pay off in June
- Transplants going out: tarragon
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.
Harney County, Oregon is in USDA Zone 6a. The average last spring frost is June 17 and the first fall frost is September 6, giving you a growing season of approximately 81 days.
At an elevation of 679 feet, Harney County receives approximately 22.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Tarragon during the growing season.
Harney County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.4
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 Harney County
How your county's soil matches Tarragon's growing requirements.
Soil pH
Your soil pH (5.6–6.4) overlaps with Tarragon's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Harney County is excellent for Tarragon — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.5%) — Tarragon will thrive.
How to Plant Tarragon
Plant Water Budget
Water stress score is 6/10 — 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 | — | 3.3" | 0" | ❄️ Dormant |
| Feb | — | 2.2" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | — | 1.5" | 0" | ❄️ Dormant |
| May | — | 1.4" | 0" | ❄️ Dormant |
| Jun | 1.7" | 0.9" | 0.8" | 💧 Light watering |
| Jul | 1.7" | 0.4" | 1.3" | 🚿 Regular watering |
| Aug | 1.7" | 0.4" | 1.3" | 🚿 Regular watering |
| Sep | 1.7" | 0.9" | 0.8" | 💧 Light watering |
| Oct | — | 2" | 0" | ❄️ Dormant |
| Nov | — | 3.6" | 0" | ❄️ Dormant |
| Dec | — | 3.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Harney 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 — Harney County, OR
Tarragon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | June 24 | Jun 24 – Jul 8 |
| Harvest | August 26 | Aug 26 – Nov 4 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Transplant Outdoors |
| July | Transplant Outdoors |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| 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: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
81 days in Harney County
Growing Tips for Tarragon in Harney County
Direct sow Tarragon outdoors after June 17 in Harney County when soil has warmed and frost danger has passed.
Your 81.0-day growing season in Harney County is tight for Tarragon (60.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.
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 Harney County, OR?
Harney County is in Zone 6a with an average last frost of June 17. Plan your Tarragon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Harney County, OR?
Harney County, Oregon is in USDA Hardiness Zone 6a. The average last spring frost is June 17 and first fall frost is September 6.
Your Harney County Garden Planner — Free
A 24-page printable planner built for Harney County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.