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When to Plant Chervil in Sac County, IA

Sac County, Iowa Zone 5a May

May to-do list for Sac County, Iowa

Each item below is timed to Sac County, Iowa's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 25
Avg. first frost October 8
Soil temp (4") 54°F
Watering Moderate
Pest pressure Low
Daylight 14.4 hrs
  1. Start chervil indoors

    These need a head start before your last frost (April 25). Sow into cells now so you're ready to transplant in a few weeks.

  2. Pick chervil

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Before June arrives, get these ready
  • 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.

Sac County, Iowa is in USDA Zone 5a. The average last spring frost is April 25 and the first fall frost is October 8, giving you a growing season of approximately 166 days.

At an elevation of 1,221 feet, Sac County receives approximately 31.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Chervil to ensure they mature before fall.

Sac County, IA (Zone 5a) Moderate season
166 days
Last Spring Frost April 25
166 growing days
First Fall Frost October 8
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Sac County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (67 days to spare)
Start indoors: Mar 17 Transplant: Apr 14 🍅 Harvest: May 26 – Jul 28
Recommended (50%) ✓ Fits season (68 days to spare)
Start indoors: Mar 21 Transplant: Apr 18 🍅 Harvest: May 30 – Aug 1
Safe Start (90%) ✓ Fits season (66 days to spare)
Start indoors: Apr 5 Transplant: May 3 🍅 Harvest: Jun 14 – Aug 16

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 Sac County

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

Soil pH

Your soil pH (5.9–6.7) overlaps with Chervil's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.8%) — 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 166-day season

Sow every 4.6 weeks. Last sowing by Aug 09 to harvest before frost.

For a dedicated fall crop, sow by Jul 30.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/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 1.3" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.2" 3.4" 0" ✅ Rainfall sufficient
May 2.2" 3.6" 0" ✅ Rainfall sufficient
Jun 2.2" 3.4" 0" ✅ Rainfall sufficient
Jul 2.2" 3.4" 0" ✅ Rainfall sufficient
Aug 2.2" 3.2" 0" ✅ Rainfall sufficient
Sep 2.2" 2.7" 0" ✅ Rainfall sufficient
Oct 2.2" 2.6" 0" ✅ Rainfall sufficient
Nov 2.5" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Sac 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 ~500 GDD — county provides 1,660 GDD Excellent fit

Chervil Planting Timeline — Sac County, IA

Chervil Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 11 Apr 11 – May 2
Harvest May 30 May 30 – Aug 1
Fall Sowing July 30 Jul 30 – Aug 13

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 Harvest
June Harvest
July Fall Sowing Harvest
August Fall Sowing Harvest
September
October
November
December
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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 5a

📆 Growing Season

166 days in Sac County

Growing Tips for Chervil in Sac County

Direct sow Chervil outdoors after April 25 in Sac County when soil has warmed and frost danger has passed.

Your generous 166.0-day season in Sac 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 Sac County, IA?

Sac County is in Zone 5a with an average last frost of April 25. Plan your Chervil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sac County, IA?

Sac County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 25 and first fall frost is October 8.

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Your Sac County Garden Planner — Free

A 24-page printable planner built for Sac 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.

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

Sources & credits

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