When to Plant Tarragon in San Juan County, NM
San Juan County, New Mexico gardeners: here's your May plan
Your garden in San Juan County, New Mexico is working on a schedule, even when you're not. Here's where you should be this May.
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Move tarragon from tray to bed
Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.
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.
San Juan County, New Mexico is in USDA Zone 7a. The average last spring frost is May 12 and the first fall frost is October 6, giving you a growing season of approximately 147 days.
At an elevation of 8,301 feet, San Juan County receives approximately 14.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°F, providing good warmth for Tarragon during the growing season. Sandy soil warms quickly in spring — great for early planting — but Tarragon will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Tarragon successfully. Mulch heavily to conserve soil moisture.
San Juan County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.3-8.5
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 San Juan County
How your county's soil matches Tarragon's growing requirements.
Soil pH
Your soil pH (7.3–8.5) is more alkaline than Tarragon prefers (6.0–7.5). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in San Juan County warms quickly in spring but drains fast. Tarragon will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Tarragon.
Organic Matter
Organic matter is low (0.9%). Add 2-3 inches of compost before planting Tarragon.
How to Plant Tarragon
Succession Planting Tarragon
Sow every 6.9 weeks. Last sowing by Jul 08 to harvest before frost.
Plant Water Budget
Water stress score is 10/10 — 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 | — | 1.1" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 0.8" | 0" | ❄️ Dormant |
| Apr | — | 0.5" | 0" | ❄️ Dormant |
| May | 1.7" | 0.3" | 1.4" | 🚿 Regular watering |
| Jun | 1.7" | 0.5" | 1.2" | 🚿 Regular watering |
| Jul | 1.7" | 2.5" | 0" | ✅ Rainfall sufficient |
| Aug | 1.7" | 2.6" | 0" | ✅ Rainfall sufficient |
| Sep | 1.7" | 2.2" | 0" | ✅ Rainfall sufficient |
| Oct | 1.7" | 1.3" | 0.4" | 💧 Light watering |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in San Juan 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 — San Juan County, NM
Tarragon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 19 | May 19 – Jun 2 |
| Harvest | July 21 | Jul 21 – Sep 29 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | Transplant Outdoors |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.4"/week · Only during dry spells
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 7a
📆 Growing Season
147 days in San Juan County
Growing Tips for Tarragon in San Juan County
Direct sow Tarragon outdoors after May 12 in San Juan County when soil has warmed and frost danger has passed.
Sandy soil in San Juan County dries quickly — mulch Tarragon with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
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 San Juan County, NM?
San Juan County is in Zone 7a with an average last frost of May 12. Plan your Tarragon planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Juan County, NM?
San Juan County, New Mexico is in USDA Hardiness Zone 7a. The average last spring frost is May 12 and first fall frost is October 6.
Your San Juan County Garden Planner — Free
A 24-page printable planner built for San Juan 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.