When to Plant Fennel in La Crosse County, WI
Your May game plan for La Crosse County, Wisconsin
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in La Crosse County, Wisconsin.
-
Move fennel from tray to bed
Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.
-
Seed fennel outdoors
Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.
Coming up in June — start thinking about
- 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.
La Crosse County, Wisconsin is in USDA Zone 5a. The average last spring frost is May 4 and the first fall frost is October 5, giving you a growing season of approximately 154 days.
At an elevation of 1,054 feet, La Crosse County receives approximately 41.1 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.
La Crosse County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-6.8
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 La Crosse County
How your county's soil matches Fennel's growing requirements.
Soil pH
Your soil pH (6.1–6.8) is within Fennel's preferred range (5.5–7.0).
Soil Texture
The silt loam soil in La Crosse County is excellent for Fennel — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.6%) — Fennel will thrive.
How to Plant Fennel
Succession Planting Fennel
Sow every 6.9 weeks. Last sowing by Jul 07 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 | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 2" | 0" | ❄️ Dormant |
| Mar | — | 2.9" | 0" | ❄️ Dormant |
| Apr | — | 4.2" | 0" | ❄️ Dormant |
| May | 2.6" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 5.1" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 4.5" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 3.9" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 2.7" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in La Crosse 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 — La Crosse County, WI
Fennel Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 9 | Mar 9 – Mar 23 |
| Transplant Outdoors | May 18 | May 18 – Jun 1 |
| Direct Sow | May 11 | May 11 – Jun 1 |
| Harvest | July 20 | Jul 20 – Aug 31 |
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 | Transplant Outdoors Direct Sow |
| 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: ideal
🗺️ USDA Zone
Zone 5a
📆 Growing Season
154 days in La Crosse County
Growing Tips for Fennel in La Crosse County
Direct sow Fennel outdoors after May 04 in La Crosse 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 La Crosse County, WI?
La Crosse County is in Zone 5a with an average last frost of May 4. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.
What planting zone is La Crosse County, WI?
La Crosse County, Wisconsin is in USDA Hardiness Zone 5a. The average last spring frost is May 4 and first fall frost is October 5.
Your La Crosse County Garden Planner — Free
A 24-page printable planner built for La Crosse 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.