When to Plant Chervil in Costilla County, CO
May to-do list for Costilla County, Colorado
A quick May briefing for Costilla County, Colorado gardeners — what's urgent, what's next, and what can wait.
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Outdoor sowing time: chervil
Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.
Before June arrives, get these ready
- Transplants going out: chervil
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.
Costilla County, Colorado is in USDA Zone 5b. The average last spring frost is June 8 and the first fall frost is September 16, giving you a growing season of approximately 100 days.
At an elevation of 5,598 feet, Costilla County receives approximately 21 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Chervil during the growing season.
Costilla County Soil Profile
Soil Type
Loam
Soil pH
6.2-8.3
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 Costilla County
How your county's soil matches Chervil's growing requirements.
Soil pH
Your soil pH (6.2–8.3) is more alkaline than Chervil prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Costilla County is excellent for Chervil — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Chervil.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Chervil.
How to Plant Chervil
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Chervil
Sow every 4.6 weeks. Last sowing by Jul 18 to harvest before frost.
For a dedicated fall crop, sow by Jul 08.
Plant Water Budget
Water stress score is 6/10 — 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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | — | 2" | 0" | ❄️ Dormant |
| May | — | 2.5" | 0" | ❄️ Dormant |
| Jun | 2.2" | 1.3" | 0.9" | 💧 Light watering |
| Jul | 2.2" | 2" | 0.2" | 💧 Light watering |
| Aug | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 1.7" | 0.5" | 💧 Light watering |
| Oct | — | 1.9" | 0" | ❄️ Dormant |
| Nov | — | 1.3" | 0" | ❄️ Dormant |
| Dec | — | 1.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Costilla County). Supplement amounts are based on average rainfall — 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" — 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.
Chervil Planting Timeline — Costilla County, CO
Chervil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | May 4 | May 4 – May 18 |
| Transplant Outdoors | June 1 | Jun 1 – Jun 15 |
| Direct Sow | May 25 | May 25 – Jun 15 |
| Harvest | July 13 | Jul 13 – Sep 14 |
| Fall Sowing | July 8 | Jul 8 – Jul 22 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Start Indoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5b
📆 Growing Season
100 days in Costilla County
Growing Tips for Chervil in Costilla County
Direct sow Chervil outdoors after June 08 in Costilla 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 →
Chervil in Other Locations
Frequently Asked Questions
When should I plant Chervil in Costilla County, CO?
Costilla County is in Zone 5b with an average last frost of June 8. Plan your Chervil planting based on this frost date — see the calendar above for exact timing.
What planting zone is Costilla County, CO?
Costilla County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is June 8 and first fall frost is September 16.
Your Costilla County Garden Planner — Free
A 24-page printable planner built for Costilla County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.