When to Plant Fennel in Knox County, NE
Your May planting checklist for Knox County, Nebraska
Each item below is timed to Knox County, Nebraska's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Time to transplant fennel
Frost risk is low now in Knox County, Nebraska. If you've been covering beds overnight, you can stop.
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Sow fennel where they'll grow
Mark the row. Birds and stray feet both have opinions about unmarked beds.
June prep starts now
- 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.
Knox County, Nebraska is in USDA Zone 5a. The average last spring frost is April 30 and the first fall frost is October 6, giving you a growing season of approximately 159 days.
At an elevation of 723 feet, Knox County receives approximately 32.8 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Fennel to ensure they mature before fall.
Knox County Soil Profile
Soil Type
Loam
Soil pH
6.3-7.7
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 Knox County
How your county's soil matches Fennel's growing requirements.
Soil pH
Your soil pH (6.3–7.7) overlaps with Fennel's range (5.5–7.0), though not a perfect match.
Soil Texture
The loam soil in Knox County is excellent for Fennel — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Fennel.
Organic Matter
Organic matter is excellent (4.0%) — Fennel will thrive.
How to Plant Fennel
Succession Planting Fennel
Sow every 6.9 weeks. Last sowing by Jul 08 to harvest before frost.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 0.8" | 0" | ❄️ Dormant |
| Feb | — | 1" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | 2.6" | 3" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 4.1" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 3.1" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 2.4" | 0.2" | 💧 Light watering |
| Nov | — | 1.3" | 0" | ❄️ Dormant |
| Dec | — | 1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Knox 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 — Knox County, NE
Fennel Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 5 | Mar 5 – Mar 19 |
| Transplant Outdoors | May 14 | May 14 – May 28 |
| Direct Sow | May 7 | May 7 – May 28 |
| Harvest | July 16 | Jul 16 – Aug 27 |
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
159 days in Knox County
Growing Tips for Fennel in Knox County
Direct sow Fennel outdoors after April 30 in Knox 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 Knox County, NE?
Knox County is in Zone 5a with an average last frost of April 30. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.
What planting zone is Knox County, NE?
Knox County, Nebraska is in USDA Hardiness Zone 5a. The average last spring frost is April 30 and first fall frost is October 6.
Your Knox County Garden Planner — Free
A 24-page printable planner built for Knox 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.