When to plant Chervil in Warren County, IL
Spring Chervil in Warren County goes in March 30–April 20, once nighttime temps stop dipping near freezing. A second sowing from August 12 to August 26 extends the harvest into fall.
When to Plant Chervil in Warren County, IL
What to do in June
Your garden in Warren County, Illinois is working on a schedule, even when you're not. Here's where you should be this June.
-
Start harvesting chervil
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
July prep starts now
- First harvests: 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.
Warren County, Illinois is in USDA Zone 5b. The average last spring frost is April 13 and the first fall frost is October 21, giving you a growing season of approximately 191 days.
At an elevation of 801 feet, Warren County receives approximately 36.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Chervil during the growing season.
Warren County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.8
Drainage
Well Drained
Chervil 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 Warren County
How your county's soil matches Chervil's growing requirements.
Soil pH
Your soil pH (5.9–6.8) overlaps with Chervil's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Warren County is excellent for Chervil — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.0%) — Chervil will thrive.
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 Aug 22 to harvest before frost.
For a dedicated fall crop, sow by Aug 12.
Chervil 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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.8" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Warren 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 — Warren County, IL
Chervil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 9 | Mar 9 – Mar 23 |
| Transplant Outdoors | April 6 | Apr 6 – Apr 20 |
| Direct Sow | March 30 | Mar 30 – Apr 20 |
| Harvest | May 18 | May 18 – Jul 20 |
| Fall Sowing | August 12 | Aug 12 – Aug 26 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| 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: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
191 days in Warren County
Growing Tips for Chervil in Warren County
Direct sow Chervil outdoors after April 13 in Warren County when soil has warmed and frost danger has passed.
Your generous 191.0-day season in Warren County allows multiple plantings of Chervil. Sow every 20.0 days for continuous harvest.
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 Warren County, IL?
Warren County is in Zone 5b with an average last frost of April 13. Plan your Chervil planting based on this frost date — see the calendar above for exact timing.
What planting zone is Warren County, IL?
Warren County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 13 and first fall frost is October 21.
When should I plant Chervil in Warren County, IL?
In Warren County, IL, plant Chervil after the last frost (around April 13) and before the first frost (around October 21). Best results when soil holds above 50°F.
What growing zone is Warren County, IL for Chervil?
Warren County sits in USDA Zone 5b. Chervil grows reliably in zones 3a through 10b, so it's a good fit here.
Can Chervil grow in Warren County's climate?
Yes — Chervil grows well in Warren County's temperate climate. Warren County averages a 191-day frost-free season, with last frost around April 13 and first frost around October 21.
Your Warren County Garden Planner — Free
A 22-page printable planner built for Warren 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.