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When to plant Fennel in McDonough County, IL

Plant Fennel in McDonough County after April 17; the prime window is April 24–May 15.

When to Plant Fennel in McDonough County, IL

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.

McDonough County, Illinois is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 17, giving you a growing season of approximately 183 days.

At an elevation of 738 feet, McDonough County receives approximately 37.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Fennel to ensure they mature before fall.

McDonough County, IL (Zone 6a) Moderate season
183 days
Last Spring Frost April 17
183 growing days
First Fall Frost October 17

McDonough County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.3

Drainage

Well Drained

Monthly Watering Guide for Fennel

Fennel needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Fennel Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 4.8" 0" ✅ Rainfall sufficient
Jun 4.3" 4.1" 0.2" 💧 Light watering
Jul 4.3" 4.6" 0" ✅ Rainfall sufficient
Aug 4.3" 3.8" 0.5" 💧 Light watering
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in McDonough County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Fennel Planting Timeline — McDonough County, IL

Fennel Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 – Mar 6
Transplant Outdoors May 1 May 1 – May 15
Direct Sow April 24 Apr 24 – May 15
Harvest July 3 Jul 3 – Aug 14

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

183 days in McDonough County

Growing Tips for McDonough County

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 McDonough County, IL?

McDonough County is in Zone 6a with an average last frost of April 17. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.

What planting zone is McDonough County, IL?

McDonough County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 17 and first fall frost is October 17.

When should I plant Fennel in McDonough County, IL?

In McDonough County, IL, plant Fennel after the last frost (around April 17) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is McDonough County, IL for Fennel?

McDonough County sits in USDA Zone 6a. Fennel grows reliably in zones 4a through 10b, so it's a good fit here.

Can Fennel grow in McDonough County's climate?

Yes — Fennel grows well in McDonough County's temperate climate. McDonough County averages a 183-day frost-free season, with last frost around April 17 and first frost around October 17.

🌱

Your McDonough County Garden Planner — Free

A 22-page printable planner built for McDonough County (Zone 6a). 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 McDonough County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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