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When to Plant Chervil in Johnson County, TN

Johnson County, Tennessee Zone 7a May

Top priorities for Johnson County, Tennessee gardeners in May

We've pulled the most time-sensitive tasks for Johnson County, Tennessee this May and put them front and centre. Tackle them in order.

Avg. last frost April 14
Avg. first frost October 22
Soil temp (4") 64°F
Watering Moderate
Pest pressure Low
Daylight 13.9 hrs
  1. Start chervil indoors

    Your window is short. These crops want several weeks of indoor growth before they go outside.

  2. Basket week: chervil

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Looking ahead to June
  • 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.

Johnson County, Tennessee is in USDA Zone 7a. The average last spring frost is April 14 and the first fall frost is October 22, giving you a growing season of approximately 191 days.

At an elevation of 404 feet, Johnson County receives approximately 43.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Chervil during the growing season.

Johnson County, TN (Zone 7a) Moderate season
191 days
Last Spring Frost April 14
191 growing days
First Fall Frost October 22
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Johnson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (93 days to spare)
Start indoors: Mar 5 Transplant: Apr 2 🍅 Harvest: May 14 – Jul 16
Recommended (50%) ✓ Fits season (93 days to spare)
Start indoors: Mar 10 Transplant: Apr 7 🍅 Harvest: May 19 – Jul 21
Safe Start (90%) ✓ Fits season (86 days to spare)
Start indoors: Mar 30 Transplant: Apr 27 🍅 Harvest: Jun 8 – Aug 10

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 Johnson County

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

Soil pH

Your soil pH (5.7–7.1) overlaps with Chervil's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Chervil.

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

5
successive plantings in your 191-day season

Sow every 4.6 weeks. Last sowing by Aug 23 to harvest before frost.

For a dedicated fall crop, sow by Aug 13.

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
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 4" 0" ❄️ Dormant
Feb 3.4" 0" ❄️ Dormant
Mar 4.5" 0" ❄️ Dormant
Apr 2.2" 3.2" 0" ✅ Rainfall sufficient
May 2.2" 3.7" 0" ✅ Rainfall sufficient
Jun 2.2" 3.4" 0" ✅ Rainfall sufficient
Jul 2.2" 4" 0" ✅ Rainfall sufficient
Aug 2.2" 4.2" 0" ✅ Rainfall sufficient
Sep 2.2" 3.5" 0" ✅ Rainfall sufficient
Oct 2.2" 2.8" 0" ✅ Rainfall sufficient
Nov 3" 0" ❄️ Dormant
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Johnson 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 ~725 GDD — county provides 2,769 GDD Excellent fit

Chervil Planting Timeline — Johnson County, TN

Chervil Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors April 7 Apr 7 – Apr 21
Direct Sow March 31 Mar 31 – Apr 21
Harvest May 19 May 19 – Jul 21
Fall Sowing August 13 Aug 13 – Aug 27

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

Month-by-Month Timeline

MonthActivities
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
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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 7a

📆 Growing Season

191 days in Johnson County

Growing Tips for Chervil in Johnson County

Direct sow Chervil outdoors after April 14 in Johnson County when soil has warmed and frost danger has passed.

Your generous 191.0-day season in Johnson 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 Johnson County, TN?

Johnson County is in Zone 7a with an average last frost of April 14. Plan your Chervil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Johnson County, TN?

Johnson County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 14 and first fall frost is October 22.

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Your Johnson County Garden Planner — Free

A 24-page printable planner built for Johnson County (Zone 7a). 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 Johnson County, TN. 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.