When to Plant Fennel (herb) in Marinette County, WI
Your May planting checklist for Marinette County, Wisconsin
A quick May briefing for Marinette County, Wisconsin gardeners — what's urgent, what's next, and what can wait.
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Move fennel (herb) from tray to bed
Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.
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Seed fennel (herb) outdoors
Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.
A few tasks this May that'll pay off in June
- Starting indoors: fennel (herb)
Herb fennel is grown for its aromatic leaves, stalks, and seeds rather than a bulb. It has a strong anise flavor and its flowers attract beneficial insects.
Marinette County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 18 and the first fall frost is October 1, giving you a growing season of approximately 136 days.
At an elevation of 782 feet, Marinette County receives approximately 31.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Fennel (herb) to ensure they mature before fall.
Marinette County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-7.3
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 Marinette County
How your county's soil matches Fennel (herb)'s growing requirements.
Soil pH
Your soil pH (5.8–7.3) overlaps with Fennel (herb)'s range (5.5–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Marinette County is excellent for Fennel (herb) — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.2%) — Fennel (herb) will thrive.
How to Plant Fennel (herb)
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Fennel (herb)
Sow every 6.9 weeks. Last sowing by Jul 03 to harvest before frost.
For a dedicated fall crop, sow by Jul 09.
Plant Water Budget
Monthly Watering Guide for Fennel (herb)
Fennel (herb) 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 (herb) Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.1" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | — | 3" | 0" | ❄️ Dormant |
| May | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jun | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Aug | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Sep | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| Oct | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Marinette County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Fennel (herb) 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 (herb) Planting Timeline — Marinette County, WI
Fennel (herb) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 6 | Apr 6 – Apr 20 |
| Transplant Outdoors | May 11 | May 11 – May 25 |
| Direct Sow | May 11 | May 11 – Jun 1 |
| Harvest | July 13 | Jul 13 – Sep 21 |
| Fall Sowing | July 9 | Jul 9 – Jul 23 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Direct Sow |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 5.5–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 4b
📆 Growing Season
136 days in Marinette County
Growing Tips for Fennel (herb) in Marinette County
Direct sow Fennel (herb) outdoors after May 18 in Marinette County when soil has warmed and frost danger has passed.
Common pests for Fennel (herb) 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 spring or fall. Unlike Florence fennel, herb fennel does not form a bulb. Harvest fronds as needed and seeds when they turn brown. Self-sows readily.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Fennel (herb) in Other Locations
Frequently Asked Questions
When should I plant Fennel (herb) in Marinette County, WI?
Marinette County is in Zone 4b with an average last frost of May 18. Plan your Fennel (herb) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Marinette County, WI?
Marinette County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 18 and first fall frost is October 1.
Your Marinette County Garden Planner — Free
A 24-page printable planner built for Marinette 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.