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When to plant Chervil in Carroll County, IA

Aim to plant Chervil in Carroll County on or after April 13; the window stays open through May 4. Carroll County's 161-day frost-free season gives you a single solid spring crop with a brief fall option. A second sowing from July 27 to August 10 extends the harvest into fall.

When to Plant Chervil in Carroll County, IA

Carroll County, Iowa Zone 5a July

July in Carroll County, Iowa — your action list

July is a pivotal month for Carroll County, Iowa gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 27
Avg. first frost October 5
Soil temp (4") 75°F
Watering Moderate
Pest pressure High
Daylight 14.8 hrs
  1. Bring in the chervil

    If you can't use it all right away, check the food-preservation section of your planner.

  2. Start your fall crops: chervil

    Mid-season soil is hot. Sow a bit deeper than the packet suggests to find cooler, damper ground.

Get ahead of August
  • First harvests: chervil

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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.

Carroll County, Iowa is in USDA Zone 5a. The average last spring frost is April 27 and the first fall frost is October 5, giving you a growing season of approximately 161 days.

At an elevation of 751 feet, Carroll County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Chervil during the growing season.

Carroll County, IA (Zone 5a) Moderate season
161 days
Last Spring Frost April 27
161 growing days
First Fall Frost October 5

Carroll County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.9

Drainage

Well Drained

Chervil Planting Risk Windows

Early Start (70% safe) ✓ Fits season (61 days to spare)
Start indoors: Mar 18 Transplant: Apr 15 🍅 Harvest: May 27 – Jul 29
Recommended (50%) ✓ Fits season (63 days to spare)
Start indoors: Mar 23 Transplant: Apr 20 🍅 Harvest: Jun 1 – Aug 3
Safe Start (90%) ✓ Fits season (61 days to spare)
Start indoors: Apr 6 Transplant: May 4 🍅 Harvest: Jun 15 – Aug 17

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 Carroll County

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

Soil pH

Your soil pH (6.1–6.9) is within Chervil's preferred range (6.0–7.0).

Soil Texture

The silt loam soil in Carroll County is excellent for Chervil — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.1%) — Chervil will thrive.

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

4
successive plantings in your 161-day season

Sow every 4.6 weeks. Last sowing by Aug 06 to harvest before frost.

For a dedicated fall crop, sow by Jul 27.

Chervil Water Budget

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

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 1.6" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 2.2" 4.2" 0" ✅ Rainfall sufficient
May 2.2" 4.6" 0" ✅ Rainfall sufficient
Jun 2.2" 4.9" 0" ✅ Rainfall sufficient
Jul 2.2" 3.6" 0" ✅ Rainfall sufficient
Aug 2.2" 4.2" 0" ✅ Rainfall sufficient
Sep 2.2" 3.5" 0" ✅ Rainfall sufficient
Oct 2.2" 3" 0" ✅ Rainfall sufficient
Nov 2.9" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Carroll 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 needs ~762 GDD — county provides 2,455 GDD Excellent fit

Chervil Planting Timeline — Carroll County, IA

Chervil Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 – Apr 6
Transplant Outdoors April 20 Apr 20 – May 4
Direct Sow April 13 Apr 13 – May 4
Harvest June 1 Jun 1 – Aug 3
Fall Sowing July 27 Jul 27 – Aug 10

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing Harvest
August Fall Sowing Harvest
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: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

161 days in Carroll County

Growing Tips for Chervil in Carroll County

Direct sow Chervil outdoors after April 27 in Carroll County when soil has warmed and frost danger has passed.

Your generous 161.0-day season in Carroll 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 →

Frequently Asked Questions

When should I plant Chervil in Carroll County, IA?

Carroll County is in Zone 5a with an average last frost of April 27. Plan your Chervil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Carroll County, IA?

Carroll County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 27 and first fall frost is October 5.

When should I plant Chervil in Carroll County, IA?

In Carroll County, IA, plant Chervil after the last frost (around April 27) and before the first frost (around October 5). Best results when soil holds above 50°F.

What growing zone is Carroll County, IA for Chervil?

Carroll County sits in USDA Zone 5a. Chervil grows reliably in zones 3a through 10b, so it's a good fit here.

Can Chervil grow in Carroll County's climate?

Yes — Chervil grows well in Carroll County's temperate climate. Carroll County averages a 161-day frost-free season, with last frost around April 27 and first frost around October 5.

🌱

Your Carroll County Garden Planner — Free

A 22-page printable planner built for Carroll County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.