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When to Plant Chervil in Brown County, WI

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.

Brown County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 8 and the first fall frost is October 6, giving you a growing season of approximately 151 days.

At an elevation of 1,235 feet, Brown County receives approximately 34.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Chervil to ensure they mature before fall.

Brown County, WI (Zone 4b) Moderate season
151 days
Last Spring Frost May 8
151 growing days
First Fall Frost October 6

Brown County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (56 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jun 3 – Aug 5
Recommended (50%) ✓ Fits season (53 days to spare)
Start indoors: Mar 27 Transplant: May 1 🍅 Harvest: Jun 12 – Aug 14
Safe Start (90%) ✓ Fits season (51 days to spare)
Start indoors: Apr 12 Transplant: May 17 🍅 Harvest: Jun 28 – Aug 30

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 Brown County

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

Soil pH

Your soil pH (6.0โ€“6.8) is within Chervil's preferred range (6.0โ€“7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) โ€” Chervil will thrive.

How to Plant Chervil

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Chervil

4
successive plantings in your 151-day season

Sow every 4.6 weeks. Last sowing by Aug 07 to harvest before frost.

For a dedicated fall crop, sow by Jul 14.

Plant Water Budget

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

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€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2.4" 0" โ„๏ธ Dormant
Apr โ€” 3.6" 0" โ„๏ธ Dormant
May 2.2" 3.9" 0" โœ… Rainfall sufficient
Jun 2.2" 4.6" 0" โœ… Rainfall sufficient
Jul 2.2" 3.6" 0" โœ… Rainfall sufficient
Aug 2.2" 3.8" 0" โœ… Rainfall sufficient
Sep 2.2" 3.3" 0" โœ… Rainfall sufficient
Oct 2.2" 2.6" 0" โœ… Rainfall sufficient
Nov โ€” 2.3" 0" โ„๏ธ Dormant
Dec โ€” 1.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Brown 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 ~650 GDD — county provides 1,963 GDD Excellent fit

Chervil Planting Timeline โ€” Brown County, WI

Chervil Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 โ€“ Apr 10
Transplant Outdoors May 1 May 1 โ€“ May 15
Direct Sow May 1 May 1 โ€“ May 22
Harvest June 12 Jun 12 โ€“ Aug 14
Fall Sowing July 14 Jul 14 โ€“ Jul 28

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

Month-by-Month Timeline

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

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

151 days in Brown County

Growing Tips for Chervil in Brown County

Direct sow Chervil outdoors after May 08 in Brown County when soil has warmed and frost danger has passed.

Your generous 151.0-day season in Brown 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 Brown County, WI?

Brown County is in Zone 4b with an average last frost of May 8. Plan your Chervil planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Brown County, WI?

Brown County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 8 and first fall frost is October 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Brown County gardeners in Zone 4b 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 Brown County, WI. Local conditions may vary. Last updated: April 2026.