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When to Plant Fennel in Gogebic County, MI

Gogebic County, Michigan Zone 4b May

May in Gogebic County, Michigan — your action list

May is a pivotal month for Gogebic County, Michigan gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 22
Avg. first frost September 25
Soil temp (4") 54°F
Watering Low
Pest pressure Low
Daylight 14.8 hrs
June prep starts now
  • Transplants going out: fennel
  • Direct-sowing: 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.

Gogebic County, Michigan is in USDA Zone 4b. The average last spring frost is May 22 and the first fall frost is September 25, giving you a growing season of approximately 126 days.

At an elevation of 695 feet, Gogebic County receives approximately 33.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Fennel to ensure they mature before fall.

Gogebic County, MI (Zone 4b) Short season
126 days
Last Spring Frost May 22
126 growing days
First Fall Frost September 25
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Gogebic County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 16 Transplant: Jun 8 🍅 Harvest: Aug 10 – Sep 21
Recommended (50%) ✓ Fits season (0 days to spare)
Start indoors: Mar 20 Transplant: Jun 12 🍅 Harvest: Aug 14 – Sep 25
Safe Start (90%) ✗ May not fit
Start indoors: Apr 4 Transplant: Jun 27 🍅 Harvest: Aug 29 – Oct 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 Gogebic County

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

Soil pH

Your soil pH (6.1–6.9) is within Fennel's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — Fennel will thrive.

How to Plant Fennel

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

Succession Planting Fennel

2
successive plantings in your 126-day season

Sow every 6.9 weeks. Last sowing by Jun 27 to harvest before frost.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
1.1″/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 1.5" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 3.1" 0" ❄️ Dormant
May 2.6" 4" 0" ✅ Rainfall sufficient
Jun 2.6" 4.2" 0" ✅ Rainfall sufficient
Jul 2.6" 3.6" 0" ✅ Rainfall sufficient
Aug 2.6" 3.6" 0" ✅ Rainfall sufficient
Sep 2.6" 3.3" 0" ✅ Rainfall sufficient
Oct 2.3" 0" ❄️ Dormant
Nov 2.3" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Gogebic 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 ~919 GDD — county provides 1,543 GDD Excellent fit

Fennel Planting Timeline — Gogebic County, MI

Fennel Planting Calendar

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors June 12 Jun 12 – Jun 26
Direct Sow June 5 Jun 5 – Jun 26
Harvest August 14 Aug 14 – Sep 25

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May
June Transplant Outdoors Direct Sow
July
August Harvest
September Harvest
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 4b

📆 Growing Season

126 days in Gogebic County

Growing Tips for Fennel in Gogebic County

Direct sow Fennel outdoors after May 22 in Gogebic 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 Gogebic County, MI?

Gogebic County is in Zone 4b with an average last frost of May 22. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.

What planting zone is Gogebic County, MI?

Gogebic County, Michigan is in USDA Hardiness Zone 4b. The average last spring frost is May 22 and first fall frost is September 25.

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Your Gogebic County Garden Planner — Free

A 24-page printable planner built for Gogebic County (Zone 4b). 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 Gogebic County, MI. 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.