Blog

When to Plant Chervil in San Miguel County, CO

Chervil is a delicate herb with a subtle anise-parsley flavor, essential in French cuisine as part of fines herbes. It prefers cool conditions and partial shade.

San Miguel County, Colorado is in USDA Zone 5a. The average last spring frost is May 31 and the first fall frost is September 21, giving you a growing season of approximately 113 days.

At an elevation of 8,402 feet, San Miguel County receives approximately 21.6 inches of rainfall annually with predominantly loam soil. Summer highs average 85ยฐF, providing good warmth for Chervil during the growing season.

San Miguel County, CO (Zone 5a) Short season
113 days
Last Spring Frost May 31
113 growing days
First Fall Frost September 21

San Miguel County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (22 days to spare)
Start indoors: Apr 8 Transplant: May 6 🍅 Harvest: Jun 17 – Aug 19
Recommended (50%) ✓ Fits season (15 days to spare)
Start indoors: Apr 26 Transplant: May 24 🍅 Harvest: Jul 5 – Sep 6
Safe Start (90%) ✓ Fits season (11 days to spare)
Start indoors: May 23 Transplant: Jun 20 🍅 Harvest: Aug 1 – Oct 3

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 238 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Chervil needs ~688 GDD — county provides 1,553 GDD Excellent fit

Chervil Planting Timeline โ€” San Miguel County, CO

Chervil Planting Calendar

Activity When Date Range
Start Indoors April 26 Apr 26 โ€“ May 10
Transplant Outdoors May 24 May 24 โ€“ Jun 7
Direct Sow May 17 May 17 โ€“ Jun 7
Fall Sowing July 13 Jul 13 โ€“ Jul 27
Harvest July 5 Jul 5 โ€“ Sep 6

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Start Indoors
May Start Indoors Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Fall Sowing Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

40โ€“60 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5a

Growing Season

113 days

Growing Tips for San Miguel County

Direct sow in early spring or fall as chervil bolts in heat. Provide shade and cool conditions. Harvest outer leaves as needed; use fresh as it loses flavor when dried.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Chervil in San Miguel County, CO?

San Miguel County is in Zone 5a with an average last frost of May 31. Plan your Chervil planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is San Miguel County, CO?

San Miguel County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 31 and first fall frost is September 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help San Miguel County gardeners in Zone 5a 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 San Miguel County, CO. Local conditions may vary. Last updated: April 2026.