When to Plant Fennel in Carroll County, TN
May in Carroll County, Tennessee — your action list
Each item below is timed to Carroll County, Tennessee's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Begin indoor sowing: fennel
Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.
Looking ahead to June
- First harvests: 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.
Carroll County, Tennessee is in USDA Zone 7b. The average last spring frost is April 4 and the first fall frost is October 27, giving you a growing season of approximately 206 days.
At an elevation of 2,921 feet, Carroll County receives approximately 40.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Fennel during the growing season.
Carroll County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.5
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 Carroll County
How your county's soil matches Fennel's growing requirements.
Soil pH
Your soil pH (5.5–6.5) is within Fennel's preferred range (5.5–7.0).
Soil Texture
The silt loam soil in Carroll County is excellent for Fennel — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.1%). Annual compost additions will help Fennel.
How to Plant Fennel
Succession Planting Fennel
Sow every 6.9 weeks. Last sowing by Jul 29 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 | — | 3.4" | 0" | ❄️ Dormant |
| Feb | — | 3.1" | 0" | ❄️ Dormant |
| Mar | — | 3.4" | 0" | ❄️ Dormant |
| Apr | 2.6" | 3.3" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 2.9" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 3.9" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 3.9" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 4.4" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 2.7" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 2.9" | 0" | ✅ Rainfall sufficient |
| Nov | — | 3" | 0" | ❄️ Dormant |
| Dec | — | 3.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Carroll 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 — Carroll County, TN
Fennel Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 14 | Feb 14 – Feb 28 |
| Transplant Outdoors | April 18 | Apr 18 – May 2 |
| Direct Sow | April 11 | Apr 11 – May 2 |
| Harvest | June 20 | Jun 20 – Aug 1 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| 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 7b
📆 Growing Season
206 days in Carroll County
Growing Tips for Fennel in Carroll County
Direct sow Fennel outdoors after April 04 in Carroll 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 Carroll County, TN?
Carroll County is in Zone 7b with an average last frost of April 4. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.
What planting zone is Carroll County, TN?
Carroll County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 4 and first fall frost is October 27.
Your Carroll County Garden Planner — Free
A 24-page printable planner built for Carroll County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.