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When to plant Fennel in Henry County, IA

Henry County gardeners should plant Fennel between April 28 and May 19 in spring. With Henry County's Zone 5b climate (last frost April 21), Fennel needs 60–90 days to mature — plant by July 16 for a full harvest.

When to Plant Fennel in Henry County, IA

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.

Henry County, Iowa is in USDA Zone 5b. The average last spring frost is April 21 and the first fall frost is October 14, giving you a growing season of approximately 176 days.

At an elevation of 879 feet, Henry County receives approximately 40.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Fennel during the growing season.

Henry County, IA (Zone 5b) Moderate season
176 days
Last Spring Frost April 21
176 growing days
First Fall Frost October 14

Henry County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Fennel Planting Timeline — Henry County, IA

Fennel Planting Calendar

Activity When Date Range
Start Indoors February 24 Feb 24 – Mar 10
Transplant Outdoors May 5 May 5 – May 19
Direct Sow April 28 Apr 28 – May 19
Harvest July 7 Jul 7 – Aug 18

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 5b

📆 Growing Season

176 days in Henry County

Growing Tips for Henry 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 Henry County, IA?

Henry County is in Zone 5b with an average last frost of April 21. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.

What planting zone is Henry County, IA?

Henry County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 21 and first fall frost is October 14.

When should I plant Fennel in Henry County, IA?

In Henry County, IA, plant Fennel after the last frost (around April 21) and before the first frost (around October 14). Best results when soil holds above 50°F.

What growing zone is Henry County, IA for Fennel?

Henry County sits in USDA Zone 5b. Fennel grows reliably in zones 4a through 10b, so it's a good fit here.

Can Fennel grow in Henry County's climate?

Yes — Fennel grows well in Henry County's temperate climate. Henry County averages a 176-day frost-free season, with last frost around April 21 and first frost around October 14.

🌱

Your Henry County Garden Planner — Free

A 22-page printable planner built for Henry County (Zone 5b). 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 Henry County, IA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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