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When to Plant Fennel in Carroll County, KY

Carroll County, Kentucky Zone 6b May

Your May gardening checklist

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 18
Avg. first frost October 20
Soil temp (4") 57°F
Watering Moderate
Pest pressure Low
Daylight 14.1 hrs
  1. Move fennel from tray to bed

    Your last frost (April 18) has passed. These warm-season crops can handle outdoor soil now.

Before June arrives, get these ready
  • Starting indoors: fennel

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Florence fennel is grown for its swollen bulb-like stem base, which has a mild anise flavor. It is crisp raw in salads and sweet when roasted or braised.

Carroll County, Kentucky is in USDA Zone 6b. The average last spring frost is April 18 and the first fall frost is October 20, giving you a growing season of approximately 185 days.

At an elevation of 3,005 feet, Carroll County receives approximately 42.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Fennel during the growing season.

Carroll County, KY (Zone 6b) Moderate season
185 days
Last Spring Frost April 18
185 growing days
First Fall Frost October 20
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Carroll County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (69 days to spare)
Start indoors: Feb 13 Transplant: Apr 24 🍅 Harvest: Jun 26 – Aug 7
Recommended (50%) ✓ Fits season (66 days to spare)
Start indoors: Feb 21 Transplant: May 2 🍅 Harvest: Jul 4 – Aug 15
Safe Start (90%) ✓ Fits season (57 days to spare)
Start indoors: Mar 13 Transplant: May 22 🍅 Harvest: Jul 24 – Sep 4

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 Fennel's growing requirements.

Soil pH

Your soil pH (5.5–7.0) is within Fennel's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Fennel.

How to Plant Fennel

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Fennel

3
successive plantings in your 185-day season

Sow every 6.9 weeks. Last sowing by Jul 22 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Fennel

Fennel needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Fennel Needs Rainfall You Supplement Action
Jan 3.7" 0" ❄️ Dormant
Feb 3.6" 0" ❄️ Dormant
Mar 3.7" 0" ❄️ Dormant
Apr 2.6" 2.8" 0" ✅ Rainfall sufficient
May 2.6" 3.5" 0" ✅ Rainfall sufficient
Jun 2.6" 4.3" 0" ✅ Rainfall sufficient
Jul 2.6" 4.2" 0" ✅ Rainfall sufficient
Aug 2.6" 4.5" 0" ✅ Rainfall sufficient
Sep 2.6" 3" 0" ✅ Rainfall sufficient
Oct 2.6" 3" 0" ✅ Rainfall sufficient
Nov 2.8" 0" ❄️ Dormant
Dec 3.3" 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.

Fennel 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.

Fennel needs ~1,312 GDD — county provides 3,237 GDD Excellent fit

Fennel Planting Timeline — Carroll County, KY

Fennel Planting Calendar

Activity When Date Range
Start Indoors February 21 Feb 21 – Mar 7
Transplant Outdoors May 2 May 2 – May 16
Direct Sow April 25 Apr 25 – May 16
Harvest July 4 Jul 4 – Aug 15

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April Direct Sow
May Transplant Outdoors Direct Sow
June
July Harvest
August Harvest
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.6"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

185 days in Carroll County

Growing Tips for Fennel in Carroll County

Direct sow Fennel outdoors after April 18 in Carroll County when soil has warmed and frost danger has passed.

Common pests for Fennel 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 late summer for fall harvest to reduce bolting. Hill soil around bulbs as they enlarge. Harvest when bulbs are tennis-ball sized before they elongate.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Peppers
  • Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Fennel in Carroll County, KY?

Carroll County is in Zone 6b with an average last frost of April 18. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.

What planting zone is Carroll County, KY?

Carroll County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 18 and first fall frost is October 20.

🌱

Your Carroll County Garden Planner — Free

A 24-page printable planner built for Carroll County (Zone 6b). 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 Carroll County, KY. 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.