When to Plant Fennel in Fond du Lac County, WI
Your May game plan for Fond du Lac County, Wisconsin
May is a pivotal month for Fond du Lac County, Wisconsin gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Transplant fennel outside
Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.
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Sow fennel where they'll grow
Mark the row. Birds and stray feet both have opinions about unmarked beds.
Before June arrives, get these ready
- Starting indoors: fennel
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.
Fond du Lac County, Wisconsin is in USDA Zone 5a. The average last spring frost is April 27 and the first fall frost is October 14, giving you a growing season of approximately 170 days.
At an elevation of 713 feet, Fond du Lac County receives approximately 32.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Fennel to ensure they mature before fall.
Fond du Lac County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.2
Drainage
Well Drained
Plant Planting Risk Windows
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 Fond du Lac County
How your county's soil matches Fennel's growing requirements.
Soil pH
Your soil pH (6.2–7.2) overlaps with Fennel's range (5.5–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Fond du Lac County is excellent for Fennel — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.1%) — Fennel will thrive.
How to Plant Fennel
Succession Planting Fennel
Sow every 6.9 weeks. Last sowing by Jul 16 to harvest before frost.
Plant Water Budget
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 | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | 2.6" | 3.5" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 3.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 3.7" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 3.4" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 2.7" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 2.8" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Fond du Lac 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 Planting Timeline — Fond du Lac County, WI
Fennel Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 2 | Mar 2 – Mar 16 |
| Transplant Outdoors | May 11 | May 11 – May 25 |
| Direct Sow | May 4 | May 4 – May 25 |
| Harvest | July 13 | Jul 13 – Aug 24 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
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: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
170 days in Fond du Lac County
Growing Tips for Fennel in Fond du Lac County
Direct sow Fennel outdoors after April 27 in Fond du Lac 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
Check more plant combinations with our Companion Planting Checker →
Fennel in Other Locations
Frequently Asked Questions
When should I plant Fennel in Fond du Lac County, WI?
Fond du Lac County is in Zone 5a with an average last frost of April 27. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.
What planting zone is Fond du Lac County, WI?
Fond du Lac County, Wisconsin is in USDA Hardiness Zone 5a. The average last spring frost is April 27 and first fall frost is October 14.
Your Fond du Lac County Garden Planner — Free
A 24-page printable planner built for Fond du Lac County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.