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When to Plant Chervil in Dolores 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.

Dolores County, Colorado is in USDA Zone 5a. The average last spring frost is June 18 and the first fall frost is September 8, giving you a growing season of approximately 82 days.

At an elevation of 7,506 feet, Dolores County receives approximately 23.1 inches of rainfall annually with predominantly loam soil. Summer highs average 85ยฐF, providing good warmth for Chervil during the growing season.

Dolores County, CO (Zone 5a) Very short season
82 days
Last Spring Frost June 18
82 growing days
First Fall Frost September 8

Dolores County Soil Profile

Soil Type

Loam

Soil pH

6.3-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: May 3 Transplant: May 31 🍅 Harvest: Jul 12 – Sep 13
Recommended (50%) ✗ May not fit
Start indoors: May 14 Transplant: Jun 11 🍅 Harvest: Jul 23 – Sep 24
Safe Start (90%) ✗ May not fit
Start indoors: May 25 Transplant: Jun 22 🍅 Harvest: Aug 3 – Oct 5

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 Dolores County

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

Soil pH

Your soil pH (6.3โ€“8.3) is more alkaline than Chervil prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

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

How to Plant Chervil

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Chervil

2
successive plantings in your 82-day season

Sow every 4.6 weeks. Last sowing by Jul 10 to harvest before frost.

For a dedicated fall crop, sow by Jun 30.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.2″/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 Chervil

Chervil needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Chervil Needs Rainfall You Supplement Action
Jan โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.2" 0" โ„๏ธ Dormant
Mar โ€” 2.1" 0" โ„๏ธ Dormant
Apr โ€” 2.6" 0" โ„๏ธ Dormant
May โ€” 3" 0" โ„๏ธ Dormant
Jun 2.2" 1.8" 0.4" ๐Ÿ’ง Light watering
Jul 2.2" 1.9" 0.3" ๐Ÿ’ง Light watering
Aug 2.2" 2.1" 0.1" ๐Ÿ’ง Light watering
Sep 2.2" 2.1" 0.1" ๐Ÿ’ง Light watering
Oct โ€” 2.2" 0" โ„๏ธ Dormant
Nov โ€” 1.7" 0" โ„๏ธ Dormant
Dec โ€” 1.2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in Dolores County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Chervil 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.

Chervil needs ~688 GDD — county provides 1,127 GDD Excellent fit

Chervil Planting Timeline โ€” Dolores County, CO

Chervil Planting Calendar

Activity When Date Range
Start Indoors May 14 May 14 โ€“ May 28
Transplant Outdoors June 11 Jun 11 โ€“ Jun 25
Direct Sow June 4 Jun 4 โ€“ Jun 25
Harvest July 23 Jul 23 โ€“ Sep 24
Fall Sowing June 30 Jun 30 โ€“ Jul 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 Start Indoors
June Transplant Outdoors Direct Sow Fall Sowing
July Fall Sowing Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

40โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

82 days in Dolores County

Growing Tips for Chervil in Dolores County

Direct sow Chervil outdoors after June 18 in Dolores County when soil has warmed and frost danger has passed.

Common pests for Chervil in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Chervil in Dolores County, CO?

Dolores County is in Zone 5a with an average last frost of June 18. Plan your Chervil planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Dolores County, CO?

Dolores County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 18 and first fall frost is September 8.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Dolores 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 Dolores County, CO. Local conditions may vary. Last updated: April 2026.