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When to Plant Tarragon in Montezuma County, CO

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.

Montezuma County, Colorado is in USDA Zone 5b. The average last spring frost is May 27 and the first fall frost is September 27, giving you a growing season of approximately 123 days.

At an elevation of 8,063 feet, Montezuma County receives approximately 15.2 inches of rainfall annually with predominantly loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Tarragon to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Tarragon successfully. Mulch heavily to conserve soil moisture.

Montezuma County, CO (Zone 5b) Short season
123 days
Last Spring Frost May 27
123 growing days
First Fall Frost September 27

Montezuma County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 26 🍅 Harvest: Jul 28 – Oct 6
Recommended (50%) ✗ May not fit
Transplant: Jun 3 🍅 Harvest: Aug 5 – Oct 14
Safe Start (90%) ✗ May not fit
Transplant: Jun 20 🍅 Harvest: Aug 22 – Oct 31

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 Montezuma County

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

Soil pH

Your soil pH (6.4โ€“7.7) overlaps with Tarragon's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The loam soil in Montezuma County is excellent for Tarragon โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Tarragon.

How to Plant Tarragon

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Tarragon

2
successive plantings in your 123-day season

Sow every 6.9 weeks. Last sowing by Jun 29 to harvest before frost.

Plant Water Budget

Plant needs
0.4″/week
Rainfall provides
0.5″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 8/10 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€” 1.1" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 1.3" 0" โ„๏ธ Dormant
Apr โ€” 1.7" 0" โ„๏ธ Dormant
May 1.7" 1.8" 0" โœ… Rainfall sufficient
Jun 1.7" 1.1" 0.6" ๐Ÿ’ง Light watering
Jul 1.7" 1.3" 0.4" ๐Ÿ’ง Light watering
Aug 1.7" 1.6" 0.1" ๐Ÿ’ง Light watering
Sep 1.7" 1.3" 0.4" ๐Ÿ’ง Light watering
Oct โ€” 1.5" 0" โ„๏ธ Dormant
Nov โ€” 1.1" 0" โ„๏ธ Dormant
Dec โ€” 0.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Montezuma 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 ~975 GDD — county provides 1,599 GDD Excellent fit

Tarragon Planting Timeline โ€” Montezuma County, CO

Tarragon Planting Calendar

Activity When Date Range
Transplant Outdoors June 3 Jun 3 โ€“ Jun 17
Harvest August 5 Aug 5 โ€“ Oct 14

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May โ€”
June Transplant Outdoors
July โ€”
August Harvest
September Harvest
October Harvest
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: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

123 days in Montezuma County

Growing Tips for Tarragon in Montezuma County

Direct sow Tarragon outdoors after May 27 in Montezuma 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 →

Frequently Asked Questions

When should I plant Tarragon in Montezuma County, CO?

Montezuma County is in Zone 5b with an average last frost of May 27. Plan your Tarragon planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Montezuma County, CO?

Montezuma County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 27 and first fall frost is September 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Montezuma County gardeners in Zone 5b 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.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Montezuma County, CO. Local conditions may vary. Last updated: April 2026.